dom/base/nsDocument.cpp
author Jeremy Chen <jeremychen@mozilla.com>
Wed, 11 Oct 2017 20:57:00 -0400
changeset 432431 c2c10508ec8d
parent 432036 35bae846b629
permissions -rw-r--r--
Bug 1403077 - Part 1: Implement the stylo blocklist mechanism. r=heycam, a=ritu In this patch, we read the stylo blocklist into nsLayoutUtils's global static variable during nsLayoutUtils::Initialize(). So, we can decide if we should fallback to use Gecko backend while updating style backend for a document. We add "layout.css.stylo-blocklist.blocked_domains" and "layout.css.stylo-blocklist.enabled" to ContentPrefs.cpp because they are read very early (during nsLayoutUtils::Initialize). MozReview-Commit-ID: IiTVf6qD9uO

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * Base class for all our document implementations.
 */

#include "AudioChannelService.h"
#include "nsDocument.h"
#include "nsIDocumentInlines.h"
#include "mozilla/AnimationComparator.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/BinarySearch.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/EffectSet.h"
#include "mozilla/EnumSet.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Likely.h"
#include "mozilla/PresShell.h"
#include "mozilla/URLExtraData.h"
#include <algorithm>

#include "mozilla/Logging.h"
#include "plstr.h"
#include "mozilla/Sprintf.h"

#include "mozilla/Telemetry.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsILoadContext.h"
#include "nsITextControlFrame.h"
#include "nsNumberControlFrame.h"
#include "nsUnicharUtils.h"
#include "nsContentList.h"
#include "nsCSSPseudoElements.h"
#include "nsIObserver.h"
#include "nsIBaseWindow.h"
#include "mozilla/css/Loader.h"
#include "mozilla/css/ImageLoader.h"
#include "nsDocShell.h"
#include "nsDocShellLoadTypes.h"
#include "nsIDocShellTreeItem.h"
#include "nsCOMArray.h"
#include "nsQueryObject.h"
#include "nsDOMClassInfo.h"
#include "mozilla/Services.h"
#include "nsScreen.h"
#include "ChildIterator.h"

#include "mozilla/AsyncEventDispatcher.h"
#include "mozilla/BasicEvents.h"
#include "mozilla/EventListenerManager.h"
#include "mozilla/EventStateManager.h"
#include "nsIDOMNodeFilter.h"

#include "nsIDOMStyleSheet.h"
#include "mozilla/dom/Attr.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "nsIDOMDOMImplementation.h"
#include "nsIDOMDocumentXBL.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/FramingChecker.h"
#include "nsGenericHTMLElement.h"
#include "mozilla/dom/CDATASection.h"
#include "mozilla/dom/ProcessingInstruction.h"
#include "nsDOMString.h"
#include "nsNodeUtils.h"
#include "nsLayoutUtils.h" // for GetFrameForPoint
#include "nsIFrame.h"
#include "nsITabChild.h"

#include "nsRange.h"
#include "nsIDOMText.h"
#include "nsIDOMComment.h"
#include "mozilla/dom/DocumentType.h"
#include "mozilla/dom/NodeIterator.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/PromiseNativeHandler.h"
#include "mozilla/dom/TreeWalker.h"

#include "nsIServiceManager.h"
#include "mozilla/dom/workers/ServiceWorkerManager.h"
#include "imgLoader.h"

#include "nsCanvasFrame.h"
#include "nsContentCID.h"
#include "nsError.h"
#include "nsPresContext.h"
#include "nsIJSON.h"
#include "nsThreadUtils.h"
#include "nsNodeInfoManager.h"
#include "nsIFileChannel.h"
#include "nsIMultiPartChannel.h"
#include "nsIRefreshURI.h"
#include "nsIWebNavigation.h"
#include "nsIScriptError.h"
#include "nsISimpleEnumerator.h"
#include "nsIRequestContext.h"
#include "nsStyleSheetService.h"

#include "nsNetUtil.h"     // for NS_NewURI
#include "nsIInputStreamChannel.h"
#include "nsIAuthPrompt.h"
#include "nsIAuthPrompt2.h"

#include "nsIScriptSecurityManager.h"
#include "nsIPermissionManager.h"
#include "nsIPrincipal.h"
#include "NullPrincipal.h"

#include "nsIDOMWindow.h"
#include "nsPIDOMWindow.h"
#include "nsIDOMElement.h"
#include "nsFocusManager.h"

// for radio group stuff
#include "nsIDOMHTMLInputElement.h"
#include "nsIRadioVisitor.h"
#include "nsIFormControl.h"

#include "nsBidiUtils.h"

#include "nsContentCreatorFunctions.h"

#include "nsIScriptContext.h"
#include "nsBindingManager.h"
#include "nsIDOMHTMLDocument.h"
#include "nsHTMLDocument.h"
#include "nsIDOMHTMLFormElement.h"
#include "nsIRequest.h"
#include "nsHostObjectProtocolHandler.h"

#include "nsCharsetSource.h"
#include "nsIParser.h"
#include "nsIContentSink.h"

#include "mozilla/EventDispatcher.h"
#include "mozilla/EventStates.h"
#include "mozilla/InternalMutationEvent.h"
#include "nsDOMCID.h"

#include "jsapi.h"
#include "nsIXPConnect.h"
#include "xpcpublic.h"
#include "nsCCUncollectableMarker.h"
#include "nsIContentPolicy.h"
#include "nsContentPolicyUtils.h"
#include "nsICategoryManager.h"
#include "nsIDocumentLoaderFactory.h"
#include "nsIDocumentLoader.h"
#include "nsIContentViewer.h"
#include "nsIXMLContentSink.h"
#include "nsIXULDocument.h"
#include "nsIPrompt.h"
#include "nsIPropertyBag2.h"
#include "mozilla/dom/PageTransitionEvent.h"
#include "mozilla/dom/StyleRuleChangeEvent.h"
#include "mozilla/dom/StyleSheetChangeEvent.h"
#include "mozilla/dom/StyleSheetApplicableStateChangeEvent.h"
#include "nsJSUtils.h"
#include "nsFrameLoader.h"
#include "nsEscape.h"
#include "nsObjectLoadingContent.h"
#include "nsHtml5TreeOpExecutor.h"
#include "mozilla/dom/HTMLLinkElement.h"
#include "mozilla/dom/HTMLMediaElement.h"
#include "mozilla/dom/HTMLIFrameElement.h"
#include "mozilla/dom/HTMLImageElement.h"
#include "mozilla/dom/MediaSource.h"
#include "mozilla/dom/FlyWebService.h"

#include "mozAutoDocUpdate.h"
#include "nsGlobalWindow.h"
#include "mozilla/Encoding.h"
#include "nsDOMNavigationTiming.h"

#include "nsSMILAnimationController.h"
#include "imgIContainer.h"
#include "nsSVGUtils.h"

#include "nsRefreshDriver.h"

// FOR CSP (autogenerated by xpidl)
#include "nsIContentSecurityPolicy.h"
#include "mozilla/dom/nsCSPContext.h"
#include "mozilla/dom/nsCSPService.h"
#include "mozilla/dom/nsCSPUtils.h"
#include "nsHTMLStyleSheet.h"
#include "nsHTMLCSSStyleSheet.h"
#include "mozilla/dom/DOMImplementation.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/Comment.h"
#include "nsTextNode.h"
#include "mozilla/dom/Link.h"
#include "mozilla/dom/HTMLCollectionBinding.h"
#include "mozilla/dom/HTMLElementBinding.h"
#include "nsXULAppAPI.h"
#include "mozilla/dom/Touch.h"
#include "mozilla/dom/TouchEvent.h"

#include "mozilla/Preferences.h"

#include "imgILoader.h"
#include "imgRequestProxy.h"
#include "nsWrapperCacheInlines.h"
#include "nsSandboxFlags.h"
#include "mozilla/dom/AnimatableBinding.h"
#include "mozilla/dom/AnonymousContent.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/DocumentFragment.h"
#include "mozilla/dom/DocumentTimeline.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/HTMLBodyElement.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "mozilla/dom/ImageTracker.h"
#include "mozilla/dom/MediaQueryList.h"
#include "mozilla/dom/NodeFilterBinding.h"
#include "mozilla/OwningNonNull.h"
#include "mozilla/dom/TabChild.h"
#include "mozilla/dom/WebComponentsBinding.h"
#include "mozilla/dom/CustomElementRegistryBinding.h"
#include "mozilla/dom/CustomElementRegistry.h"
#include "mozilla/dom/TimeoutManager.h"
#include "mozilla/ExtensionPolicyService.h"
#include "nsFrame.h"
#include "nsDOMCaretPosition.h"
#include "nsIDOMHTMLTextAreaElement.h"
#include "nsViewportInfo.h"
#include "mozilla/StaticPtr.h"
#include "nsITextControlElement.h"
#include "nsIDOMNSEditableElement.h"
#include "nsIEditor.h"
#include "nsIDOMCSSStyleRule.h"
#include "mozilla/css/StyleRule.h"
#include "nsIHttpChannelInternal.h"
#include "nsISecurityConsoleMessage.h"
#include "nsCharSeparatedTokenizer.h"
#include "mozilla/dom/XPathEvaluator.h"
#include "mozilla/dom/XPathNSResolverBinding.h"
#include "mozilla/dom/XPathResult.h"
#include "nsIDocumentEncoder.h"
#include "nsIDocumentActivity.h"
#include "nsIStructuredCloneContainer.h"
#include "nsIMutableArray.h"
#include "mozilla/dom/DOMStringList.h"
#include "nsWindowSizes.h"
#include "mozilla/dom/Location.h"
#include "mozilla/dom/FontFaceSet.h"
#include "gfxPrefs.h"
#include "nsISupportsPrimitives.h"
#include "mozilla/StyleSetHandle.h"
#include "mozilla/StyleSetHandleInlines.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/StyleSheetInlines.h"
#include "mozilla/dom/SVGSVGElement.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/TabGroup.h"
#ifdef MOZ_XUL
#include "mozilla/dom/ContainerBoxObject.h"
#include "mozilla/dom/ListBoxObject.h"
#include "mozilla/dom/MenuBoxObject.h"
#include "mozilla/dom/PopupBoxObject.h"
#include "mozilla/dom/ScrollBoxObject.h"
#include "mozilla/dom/TreeBoxObject.h"
#endif
#include "nsIPresShellInlines.h"

#include "mozilla/DocLoadingTimelineMarker.h"

#include "nsISpeculativeConnect.h"

#include "mozilla/MediaManager.h"

#include "nsIURIClassifier.h"
#include "mozilla/DocumentStyleRootIterator.h"
#include "mozilla/ServoRestyleManager.h"
#include "mozilla/ClearOnShutdown.h"

using namespace mozilla;
using namespace mozilla::dom;

typedef nsTArray<Link*> LinkArray;

static LazyLogModule gDocumentLeakPRLog("DocumentLeak");
static LazyLogModule gCspPRLog("CSP");

static const char kChromeInContentPref[] = "security.allow_chrome_frames_inside_content";
static bool sChromeInContentAllowed = false;
static bool sChromeInContentPrefCached = false;

static nsresult
GetHttpChannelHelper(nsIChannel* aChannel, nsIHttpChannel** aHttpChannel)
{
  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel);
  if (httpChannel) {
    httpChannel.forget(aHttpChannel);
    return NS_OK;
  }

  nsCOMPtr<nsIMultiPartChannel> multipart = do_QueryInterface(aChannel);
  if (!multipart) {
    *aHttpChannel = nullptr;
    return NS_OK;
  }

  nsCOMPtr<nsIChannel> baseChannel;
  nsresult rv = multipart->GetBaseChannel(getter_AddRefs(baseChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  httpChannel = do_QueryInterface(baseChannel);
  httpChannel.forget(aHttpChannel);

  return NS_OK;
}

////////////////////////////////////////////////////////////////////
// PrincipalFlashClassifier

// Classify the flash based on the document principal.
// The usage of this class is as follows:
//
// 1) Call AsyncClassify() as early as possible to asynchronously do
//    classification against all the flash blocking related tables
//    via nsIURIClassifier.asyncClassifyLocalWithTables.
//
// 2) At any time you need the classification result, call Result()
//    and it is guaranteed to give you the result. Note that you have
//    to specify "aIsThirdParty" to the function so please make sure
//    you can already correctly decide if the document is third-party.
//
//    Behind the scenes, the sync classification API
//    (nsIURIClassifier.classifyLocalWithTable) may be called as a fallback to
//    synchronously get the result if the asyncClassifyLocalWithTables hasn't
//    been done yet.
//
// 3) You can call Result() as many times as you want and only the first time
//    it may unfortunately call the blocking sync API. The subsequent call
//    will just return the result that came out at the first time.
//
class PrincipalFlashClassifier final : public nsIURIClassifierCallback
{
public:
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIURICLASSIFIERCALLBACK

  PrincipalFlashClassifier();

  // Fire async classification based on the given principal.
  void AsyncClassify(nsIPrincipal* aPrincipal);

  // Would block if the result hasn't come out.
  mozilla::dom::FlashClassification ClassifyMaybeSync(nsIPrincipal* aPrincipal,
                                           bool aIsThirdParty);

private:
 ~PrincipalFlashClassifier() = default;

  void Reset();
  bool EnsureUriClassifier();
  mozilla::dom::FlashClassification CheckIfClassifyNeeded(nsIPrincipal* aPrincipal);
  mozilla::dom::FlashClassification Resolve(bool aIsThirdParty);
  mozilla::dom::FlashClassification AsyncClassifyInternal(nsIPrincipal* aPrincipal);
  void GetClassificationTables(bool aIsThirdParty, nsACString& aTables);

  // For the fallback sync classification.
  nsCOMPtr<nsIURI> mClassificationURI;

  nsCOMPtr<nsIURIClassifier> mUriClassifier;
  bool mAsyncClassified;
  nsTArray<nsCString> mMatchedTables;
  mozilla::dom::FlashClassification mResult;
};


#define NAME_NOT_VALID ((nsSimpleContentList*)1)

nsIdentifierMapEntry::~nsIdentifierMapEntry()
{
}

void
nsIdentifierMapEntry::Traverse(nsCycleCollectionTraversalCallback* aCallback)
{
  NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                     "mIdentifierMap mNameContentList");
  aCallback->NoteXPCOMChild(static_cast<nsIDOMNodeList*>(mNameContentList));

  if (mImageElement) {
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mIdentifierMap mImageElement element");
    nsIContent* imageElement = mImageElement;
    aCallback->NoteXPCOMChild(imageElement);
  }
}

bool
nsIdentifierMapEntry::IsEmpty()
{
  return mIdContentList.IsEmpty() && !mNameContentList &&
         !mChangeCallbacks && !mImageElement;
}

Element*
nsIdentifierMapEntry::GetIdElement()
{
  return mIdContentList.SafeElementAt(0);
}

Element*
nsIdentifierMapEntry::GetImageIdElement()
{
  return mImageElement ? mImageElement.get() : GetIdElement();
}

void
nsIdentifierMapEntry::AppendAllIdContent(nsCOMArray<nsIContent>* aElements)
{
  for (size_t i = 0; i < mIdContentList.Length(); ++i) {
    aElements->AppendObject(mIdContentList[i]);
  }
}

void
nsIdentifierMapEntry::AddContentChangeCallback(nsIDocument::IDTargetObserver aCallback,
                                               void* aData, bool aForImage)
{
  if (!mChangeCallbacks) {
    mChangeCallbacks = new nsTHashtable<ChangeCallbackEntry>;
  }

  ChangeCallback cc = { aCallback, aData, aForImage };
  mChangeCallbacks->PutEntry(cc);
}

void
nsIdentifierMapEntry::RemoveContentChangeCallback(nsIDocument::IDTargetObserver aCallback,
                                                  void* aData, bool aForImage)
{
  if (!mChangeCallbacks)
    return;
  ChangeCallback cc = { aCallback, aData, aForImage };
  mChangeCallbacks->RemoveEntry(cc);
  if (mChangeCallbacks->Count() == 0) {
    mChangeCallbacks = nullptr;
  }
}

void
nsIdentifierMapEntry::FireChangeCallbacks(Element* aOldElement,
                                          Element* aNewElement,
                                          bool aImageOnly)
{
  if (!mChangeCallbacks)
    return;

  for (auto iter = mChangeCallbacks->ConstIter(); !iter.Done(); iter.Next()) {
    nsIdentifierMapEntry::ChangeCallbackEntry* entry = iter.Get();
    // Don't fire image changes for non-image observers, and don't fire element
    // changes for image observers when an image override is active.
    if (entry->mKey.mForImage ? (mImageElement && !aImageOnly) : aImageOnly) {
      continue;
    }

    if (!entry->mKey.mCallback(aOldElement, aNewElement, entry->mKey.mData)) {
      iter.Remove();
    }
  }
}

namespace {

struct PositionComparator
{
  Element* const mElement;
  explicit PositionComparator(Element* const aElement) : mElement(aElement) {}

  int operator()(void* aElement) const {
    Element* curElement = static_cast<Element*>(aElement);
    if (mElement == curElement) {
      return 0;
    }
    if (nsContentUtils::PositionIsBefore(mElement, curElement)) {
      return -1;
    }
    return 1;
  }
};

} // namespace

bool
nsIdentifierMapEntry::AddIdElement(Element* aElement)
{
  NS_PRECONDITION(aElement, "Must have element");
  NS_PRECONDITION(!mIdContentList.Contains(nullptr),
                  "Why is null in our list?");

#ifdef DEBUG
  Element* currentElement = mIdContentList.SafeElementAt(0);
#endif

  // Common case
  if (mIdContentList.IsEmpty()) {
    if (!mIdContentList.AppendElement(aElement))
      return false;
    NS_ASSERTION(currentElement == nullptr, "How did that happen?");
    FireChangeCallbacks(nullptr, aElement);
    return true;
  }

  // We seem to have multiple content nodes for the same id, or XUL is messing
  // with us.  Search for the right place to insert the content.

  size_t idx;
  if (BinarySearchIf(mIdContentList, 0, mIdContentList.Length(),
                     PositionComparator(aElement), &idx)) {
    // Already in the list, so already in the right spot.  Get out of here.
    // XXXbz this only happens because XUL does all sorts of random
    // UpdateIdTableEntry calls.  Hate, hate, hate!
    return true;
  }

  if (!mIdContentList.InsertElementAt(idx, aElement)) {
    return false;
  }

  if (idx == 0) {
    Element* oldElement = mIdContentList.SafeElementAt(1);
    NS_ASSERTION(currentElement == oldElement, "How did that happen?");
    FireChangeCallbacks(oldElement, aElement);
  }
  return true;
}

void
nsIdentifierMapEntry::RemoveIdElement(Element* aElement)
{
  NS_PRECONDITION(aElement, "Missing element");

  // This should only be called while the document is in an update.
  // Assertions near the call to this method guarantee this.

  // This could fire in OOM situations
  // Only assert this in HTML documents for now as XUL does all sorts of weird
  // crap.
  NS_ASSERTION(!aElement->OwnerDoc()->IsHTMLDocument() ||
               mIdContentList.Contains(aElement),
               "Removing id entry that doesn't exist");

  // XXXbz should this ever Compact() I guess when all the content is gone
  // we'll just get cleaned up in the natural order of things...
  Element* currentElement = mIdContentList.SafeElementAt(0);
  mIdContentList.RemoveElement(aElement);
  if (currentElement == aElement) {
    FireChangeCallbacks(currentElement, mIdContentList.SafeElementAt(0));
  }
}

void
nsIdentifierMapEntry::SetImageElement(Element* aElement)
{
  Element* oldElement = GetImageIdElement();
  mImageElement = aElement;
  Element* newElement = GetImageIdElement();
  if (oldElement != newElement) {
    FireChangeCallbacks(oldElement, newElement, true);
  }
}

namespace mozilla {
namespace dom {
class SimpleHTMLCollection final : public nsSimpleContentList
                                 , public nsIHTMLCollection
{
public:
  explicit SimpleHTMLCollection(nsINode* aRoot) : nsSimpleContentList(aRoot) {}

  NS_DECL_ISUPPORTS_INHERITED

  // nsIDOMHTMLCollection
  NS_DECL_NSIDOMHTMLCOLLECTION

  virtual nsINode* GetParentObject() override
  {
    return nsSimpleContentList::GetParentObject();
  }
  virtual Element* GetElementAt(uint32_t aIndex) override
  {
    return mElements.SafeElementAt(aIndex)->AsElement();
  }

  virtual Element* GetFirstNamedElement(const nsAString& aName,
                                        bool& aFound) override
  {
    aFound = false;
    nsCOMPtr<nsIAtom> name = NS_Atomize(aName);
    for (uint32_t i = 0; i < mElements.Length(); i++) {
      MOZ_DIAGNOSTIC_ASSERT(mElements[i]);
      Element* element = mElements[i]->AsElement();
      if (element->GetID() == name ||
          (element->HasName() &&
           element->GetParsedAttr(nsGkAtoms::name)->GetAtomValue() == name)) {
        aFound = true;
        return element;
      }
    }
    return nullptr;
  }

  virtual void GetSupportedNames(nsTArray<nsString>& aNames) override
  {
    AutoTArray<nsIAtom*, 8> atoms;
    for (uint32_t i = 0; i < mElements.Length(); i++) {
      MOZ_DIAGNOSTIC_ASSERT(mElements[i]);
      Element* element = mElements[i]->AsElement();

      nsIAtom* id = element->GetID();
      MOZ_ASSERT(id != nsGkAtoms::_empty);
      if (id && !atoms.Contains(id)) {
        atoms.AppendElement(id);
      }

      if (element->HasName()) {
        nsIAtom* name = element->GetParsedAttr(nsGkAtoms::name)->GetAtomValue();
        MOZ_ASSERT(name && name != nsGkAtoms::_empty);
        if (name && !atoms.Contains(name)) {
          atoms.AppendElement(name);
        }
      }
    }

    nsString* names = aNames.AppendElements(atoms.Length());
    for (uint32_t i = 0; i < atoms.Length(); i++) {
      atoms[i]->ToString(names[i]);
    }
  }

  virtual JSObject* GetWrapperPreserveColorInternal() override
  {
    return nsWrapperCache::GetWrapperPreserveColor();
  }
  virtual void PreserveWrapperInternal(nsISupports* aScriptObjectHolder) override
  {
    nsWrapperCache::PreserveWrapper(aScriptObjectHolder);
  }
  virtual JSObject* WrapObject(JSContext *aCx,
                               JS::Handle<JSObject*> aGivenProto) override
  {
    return HTMLCollectionBinding::Wrap(aCx, this, aGivenProto);
  }

  using nsBaseContentList::Length;
  using nsBaseContentList::Item;
  using nsIHTMLCollection::NamedItem;

private:
  virtual ~SimpleHTMLCollection() {}
};

NS_IMPL_ISUPPORTS_INHERITED(SimpleHTMLCollection, nsSimpleContentList,
                            nsIHTMLCollection, nsIDOMHTMLCollection)

NS_IMETHODIMP
SimpleHTMLCollection::GetLength(uint32_t* aLength)
{
  *aLength = Length();
  return NS_OK;
}

NS_IMETHODIMP
SimpleHTMLCollection::Item(uint32_t aIdx, nsIDOMNode** aRetVal)
{
  nsCOMPtr<nsIDOMNode> retVal = Item(aIdx)->AsDOMNode();
  retVal.forget(aRetVal);
  return NS_OK;
}

NS_IMETHODIMP
SimpleHTMLCollection::NamedItem(const nsAString& aName, nsIDOMNode** aRetVal)
{
  nsCOMPtr<nsIDOMNode> retVal = NamedItem(aName)->AsDOMNode();
  retVal.forget(aRetVal);
  return NS_OK;
}

} // namespace dom
} // namespace mozilla

void
nsIdentifierMapEntry::AddNameElement(nsINode* aNode, Element* aElement)
{
  if (!mNameContentList) {
    mNameContentList = new SimpleHTMLCollection(aNode);
  }

  mNameContentList->AppendElement(aElement);
}

void
nsIdentifierMapEntry::RemoveNameElement(Element* aElement)
{
  if (mNameContentList) {
    mNameContentList->RemoveElement(aElement);
  }
}

bool
nsIdentifierMapEntry::HasIdElementExposedAsHTMLDocumentProperty()
{
  Element* idElement = GetIdElement();
  return idElement &&
         nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(idElement);
}

size_t
nsIdentifierMapEntry::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
  return mKey.mString.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
}

// Helper structs for the content->subdoc map

class SubDocMapEntry : public PLDHashEntryHdr
{
public:
  // Both of these are strong references
  Element *mKey; // must be first, to look like PLDHashEntryStub
  nsIDocument *mSubDocument;
};


/**
 * A struct that holds all the information about a radio group.
 */
struct nsRadioGroupStruct
{
  nsRadioGroupStruct()
    : mRequiredRadioCount(0)
    , mGroupSuffersFromValueMissing(false)
  {}

  /**
   * A strong pointer to the currently selected radio button.
   */
  RefPtr<HTMLInputElement> mSelectedRadioButton;
  nsCOMArray<nsIFormControl> mRadioButtons;
  uint32_t mRequiredRadioCount;
  bool mGroupSuffersFromValueMissing;
};


nsDOMStyleSheetList::nsDOMStyleSheetList(nsIDocument *aDocument)
{
  mLength = -1;
  // Not reference counted to avoid circular references.
  // The document will tell us when its going away.
  mDocument = aDocument;
  mDocument->AddObserver(this);
}

nsDOMStyleSheetList::~nsDOMStyleSheetList()
{
  if (mDocument) {
    mDocument->RemoveObserver(this);
  }
}

NS_IMPL_ISUPPORTS_INHERITED(nsDOMStyleSheetList, StyleSheetList,
                            nsIDocumentObserver,
                            nsIMutationObserver)

uint32_t
nsDOMStyleSheetList::Length()
{
  if (!mDocument) {
    return 0;
  }

  // XXX Find the number and then cache it. We'll use the
  // observer notification to figure out if new ones have
  // been added or removed.
  if (-1 == mLength) {
    mLength = mDocument->GetNumberOfStyleSheets();
  }
  return mLength;
}

StyleSheet*
nsDOMStyleSheetList::IndexedGetter(uint32_t aIndex, bool& aFound)
{
  if (!mDocument || aIndex >= (uint32_t)mDocument->GetNumberOfStyleSheets()) {
    aFound = false;
    return nullptr;
  }
  aFound = true;
  return mDocument->GetStyleSheetAt(aIndex);
}

void
nsDOMStyleSheetList::NodeWillBeDestroyed(const nsINode *aNode)
{
  mDocument = nullptr;
}

void
nsDOMStyleSheetList::StyleSheetAdded(StyleSheet* aStyleSheet,
                                     bool aDocumentSheet)
{
  if (aDocumentSheet && -1 != mLength) {
    mLength++;
  }
}

void
nsDOMStyleSheetList::StyleSheetRemoved(StyleSheet* aStyleSheet,
                                       bool aDocumentSheet)
{
  if (aDocumentSheet && -1 != mLength) {
    mLength--;
  }
}

// nsOnloadBlocker implementation
NS_IMPL_ISUPPORTS(nsOnloadBlocker, nsIRequest)

NS_IMETHODIMP
nsOnloadBlocker::GetName(nsACString &aResult)
{
  aResult.AssignLiteral("about:document-onload-blocker");
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::IsPending(bool *_retval)
{
  *_retval = true;
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::GetStatus(nsresult *status)
{
  *status = NS_OK;
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::Cancel(nsresult status)
{
  return NS_OK;
}
NS_IMETHODIMP
nsOnloadBlocker::Suspend(void)
{
  return NS_OK;
}
NS_IMETHODIMP
nsOnloadBlocker::Resume(void)
{
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::GetLoadGroup(nsILoadGroup * *aLoadGroup)
{
  *aLoadGroup = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::SetLoadGroup(nsILoadGroup * aLoadGroup)
{
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::GetLoadFlags(nsLoadFlags *aLoadFlags)
{
  *aLoadFlags = nsIRequest::LOAD_NORMAL;
  return NS_OK;
}

NS_IMETHODIMP
nsOnloadBlocker::SetLoadFlags(nsLoadFlags aLoadFlags)
{
  return NS_OK;
}

// ==================================================================

nsExternalResourceMap::nsExternalResourceMap()
  : mHaveShutDown(false)
{
}

nsIDocument*
nsExternalResourceMap::RequestResource(nsIURI* aURI,
                                       nsINode* aRequestingNode,
                                       nsDocument* aDisplayDocument,
                                       ExternalResourceLoad** aPendingLoad)
{
  // If we ever start allowing non-same-origin loads here, we might need to do
  // something interesting with aRequestingPrincipal even for the hashtable
  // gets.
  NS_PRECONDITION(aURI, "Must have a URI");
  NS_PRECONDITION(aRequestingNode, "Must have a node");
  *aPendingLoad = nullptr;
  if (mHaveShutDown) {
    return nullptr;
  }

  // First, make sure we strip the ref from aURI.
  nsCOMPtr<nsIURI> clone;
  nsresult rv = aURI->CloneIgnoringRef(getter_AddRefs(clone));
  if (NS_FAILED(rv) || !clone) {
    return nullptr;
  }

  ExternalResource* resource;
  mMap.Get(clone, &resource);
  if (resource) {
    return resource->mDocument;
  }

  RefPtr<PendingLoad>& loadEntry = mPendingLoads.GetOrInsert(clone);
  if (loadEntry) {
    RefPtr<PendingLoad> load(loadEntry);
    load.forget(aPendingLoad);
    return nullptr;
  }

  RefPtr<PendingLoad> load(new PendingLoad(aDisplayDocument));
  loadEntry = load;

  if (NS_FAILED(load->StartLoad(clone, aRequestingNode))) {
    // Make sure we don't thrash things by trying this load again, since
    // chances are it failed for good reasons (security check, etc).
    AddExternalResource(clone, nullptr, nullptr, aDisplayDocument);
  } else {
    load.forget(aPendingLoad);
  }

  return nullptr;
}

void
nsExternalResourceMap::EnumerateResources(nsIDocument::nsSubDocEnumFunc aCallback,
                                          void* aData)
{
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    nsExternalResourceMap::ExternalResource* resource = iter.UserData();
    if (resource->mDocument && !aCallback(resource->mDocument, aData)) {
      break;
    }
  }
}

void
nsExternalResourceMap::Traverse(nsCycleCollectionTraversalCallback* aCallback) const
{
  // mPendingLoads will get cleared out as the requests complete, so
  // no need to worry about those here.
  for (auto iter = mMap.ConstIter(); !iter.Done(); iter.Next()) {
    nsExternalResourceMap::ExternalResource* resource = iter.UserData();

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mDocument");
    aCallback->NoteXPCOMChild(resource->mDocument);

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mViewer");
    aCallback->NoteXPCOMChild(resource->mViewer);

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mLoadGroup");
    aCallback->NoteXPCOMChild(resource->mLoadGroup);
  }
}

void
nsExternalResourceMap::HideViewers()
{
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    nsCOMPtr<nsIContentViewer> viewer = iter.UserData()->mViewer;
    if (viewer) {
      viewer->Hide();
    }
  }
}

void
nsExternalResourceMap::ShowViewers()
{
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    nsCOMPtr<nsIContentViewer> viewer = iter.UserData()->mViewer;
    if (viewer) {
      viewer->Show();
    }
  }
}

void
TransferZoomLevels(nsIDocument* aFromDoc,
                   nsIDocument* aToDoc)
{
  MOZ_ASSERT(aFromDoc && aToDoc,
             "transferring zoom levels from/to null doc");

  nsIPresShell* fromShell = aFromDoc->GetShell();
  if (!fromShell)
    return;

  nsPresContext* fromCtxt = fromShell->GetPresContext();
  if (!fromCtxt)
    return;

  nsIPresShell* toShell = aToDoc->GetShell();
  if (!toShell)
    return;

  nsPresContext* toCtxt = toShell->GetPresContext();
  if (!toCtxt)
    return;

  toCtxt->SetFullZoom(fromCtxt->GetFullZoom());
  toCtxt->SetBaseMinFontSize(fromCtxt->BaseMinFontSize());
  toCtxt->SetTextZoom(fromCtxt->TextZoom());
  toCtxt->SetOverrideDPPX(fromCtxt->GetOverrideDPPX());
}

void
TransferShowingState(nsIDocument* aFromDoc, nsIDocument* aToDoc)
{
  MOZ_ASSERT(aFromDoc && aToDoc,
             "transferring showing state from/to null doc");

  if (aFromDoc->IsShowing()) {
    aToDoc->OnPageShow(true, nullptr);
  }
}

nsresult
nsExternalResourceMap::AddExternalResource(nsIURI* aURI,
                                           nsIContentViewer* aViewer,
                                           nsILoadGroup* aLoadGroup,
                                           nsIDocument* aDisplayDocument)
{
  NS_PRECONDITION(aURI, "Unexpected call");
  NS_PRECONDITION((aViewer && aLoadGroup) || (!aViewer && !aLoadGroup),
                  "Must have both or neither");

  RefPtr<PendingLoad> load;
  mPendingLoads.Remove(aURI, getter_AddRefs(load));

  nsresult rv = NS_OK;

  nsCOMPtr<nsIDocument> doc;
  if (aViewer) {
    doc = aViewer->GetDocument();
    NS_ASSERTION(doc, "Must have a document");

    nsCOMPtr<nsIXULDocument> xulDoc = do_QueryInterface(doc);
    if (xulDoc) {
      // We don't handle XUL stuff here yet.
      rv = NS_ERROR_NOT_AVAILABLE;
    } else {
      doc->SetDisplayDocument(aDisplayDocument);

      // Make sure that hiding our viewer will tear down its presentation.
      aViewer->SetSticky(false);

      rv = aViewer->Init(nullptr, nsIntRect(0, 0, 0, 0));
      if (NS_SUCCEEDED(rv)) {
        rv = aViewer->Open(nullptr, nullptr);
      }
    }

    if (NS_FAILED(rv)) {
      doc = nullptr;
      aViewer = nullptr;
      aLoadGroup = nullptr;
    }
  }

  ExternalResource* newResource = new ExternalResource();
  mMap.Put(aURI, newResource);

  newResource->mDocument = doc;
  newResource->mViewer = aViewer;
  newResource->mLoadGroup = aLoadGroup;
  if (doc) {
    TransferZoomLevels(aDisplayDocument, doc);
    TransferShowingState(aDisplayDocument, doc);
  }

  const nsTArray< nsCOMPtr<nsIObserver> > & obs = load->Observers();
  for (uint32_t i = 0; i < obs.Length(); ++i) {
    obs[i]->Observe(doc, "external-resource-document-created", nullptr);
  }

  return rv;
}

NS_IMPL_ISUPPORTS(nsExternalResourceMap::PendingLoad,
                  nsIStreamListener,
                  nsIRequestObserver)

NS_IMETHODIMP
nsExternalResourceMap::PendingLoad::OnStartRequest(nsIRequest *aRequest,
                                                   nsISupports *aContext)
{
  nsExternalResourceMap& map = mDisplayDocument->ExternalResourceMap();
  if (map.HaveShutDown()) {
    return NS_BINDING_ABORTED;
  }

  nsCOMPtr<nsIContentViewer> viewer;
  nsCOMPtr<nsILoadGroup> loadGroup;
  nsresult rv = SetupViewer(aRequest, getter_AddRefs(viewer),
                            getter_AddRefs(loadGroup));

  // Make sure to do this no matter what
  nsresult rv2 = map.AddExternalResource(mURI, viewer, loadGroup,
                                         mDisplayDocument);
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (NS_FAILED(rv2)) {
    mTargetListener = nullptr;
    return rv2;
  }

  return mTargetListener->OnStartRequest(aRequest, aContext);
}

nsresult
nsExternalResourceMap::PendingLoad::SetupViewer(nsIRequest* aRequest,
                                                nsIContentViewer** aViewer,
                                                nsILoadGroup** aLoadGroup)
{
  NS_PRECONDITION(!mTargetListener, "Unexpected call to OnStartRequest");
  *aViewer = nullptr;
  *aLoadGroup = nullptr;

  nsCOMPtr<nsIChannel> chan(do_QueryInterface(aRequest));
  NS_ENSURE_TRUE(chan, NS_ERROR_UNEXPECTED);

  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aRequest));
  if (httpChannel) {
    bool requestSucceeded;
    if (NS_FAILED(httpChannel->GetRequestSucceeded(&requestSucceeded)) ||
        !requestSucceeded) {
      // Bail out on this load, since it looks like we have an HTTP error page
      return NS_BINDING_ABORTED;
    }
  }

  nsAutoCString type;
  chan->GetContentType(type);

  nsCOMPtr<nsILoadGroup> loadGroup;
  chan->GetLoadGroup(getter_AddRefs(loadGroup));

  // Give this document its own loadgroup
  nsCOMPtr<nsILoadGroup> newLoadGroup =
        do_CreateInstance(NS_LOADGROUP_CONTRACTID);
  NS_ENSURE_TRUE(newLoadGroup, NS_ERROR_OUT_OF_MEMORY);
  newLoadGroup->SetLoadGroup(loadGroup);

  nsCOMPtr<nsIInterfaceRequestor> callbacks;
  loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));

  nsCOMPtr<nsIInterfaceRequestor> newCallbacks =
    new LoadgroupCallbacks(callbacks);
  newLoadGroup->SetNotificationCallbacks(newCallbacks);

  // This is some serious hackery cribbed from docshell
  nsCOMPtr<nsICategoryManager> catMan =
    do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
  NS_ENSURE_TRUE(catMan, NS_ERROR_NOT_AVAILABLE);
  nsCString contractId;
  nsresult rv = catMan->GetCategoryEntry("Gecko-Content-Viewers", type.get(),
                                         getter_Copies(contractId));
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIDocumentLoaderFactory> docLoaderFactory =
    do_GetService(contractId.get());
  NS_ENSURE_TRUE(docLoaderFactory, NS_ERROR_NOT_AVAILABLE);

  nsCOMPtr<nsIContentViewer> viewer;
  nsCOMPtr<nsIStreamListener> listener;
  rv = docLoaderFactory->CreateInstance("external-resource", chan, newLoadGroup,
                                        type, nullptr, nullptr,
                                        getter_AddRefs(listener),
                                        getter_AddRefs(viewer));
  NS_ENSURE_SUCCESS(rv, rv);
  NS_ENSURE_TRUE(viewer, NS_ERROR_UNEXPECTED);

  nsCOMPtr<nsIParser> parser = do_QueryInterface(listener);
  if (!parser) {
    /// We don't want to deal with the various fake documents yet
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  // We can't handle HTML and other weird things here yet.
  nsIContentSink* sink = parser->GetContentSink();
  nsCOMPtr<nsIXMLContentSink> xmlSink = do_QueryInterface(sink);
  if (!xmlSink) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  listener.swap(mTargetListener);
  viewer.forget(aViewer);
  newLoadGroup.forget(aLoadGroup);
  return NS_OK;
}

NS_IMETHODIMP
nsExternalResourceMap::PendingLoad::OnDataAvailable(nsIRequest* aRequest,
                                                    nsISupports* aContext,
                                                    nsIInputStream* aStream,
                                                    uint64_t aOffset,
                                                    uint32_t aCount)
{
  NS_PRECONDITION(mTargetListener, "Shouldn't be getting called!");
  if (mDisplayDocument->ExternalResourceMap().HaveShutDown()) {
    return NS_BINDING_ABORTED;
  }
  return mTargetListener->OnDataAvailable(aRequest, aContext, aStream, aOffset,
                                          aCount);
}

NS_IMETHODIMP
nsExternalResourceMap::PendingLoad::OnStopRequest(nsIRequest* aRequest,
                                                  nsISupports* aContext,
                                                  nsresult aStatus)
{
  // mTargetListener might be null if SetupViewer or AddExternalResource failed
  if (mTargetListener) {
    nsCOMPtr<nsIStreamListener> listener;
    mTargetListener.swap(listener);
    return listener->OnStopRequest(aRequest, aContext, aStatus);
  }

  return NS_OK;
}

nsresult
nsExternalResourceMap::PendingLoad::StartLoad(nsIURI* aURI,
                                              nsINode* aRequestingNode)
{
  NS_PRECONDITION(aURI, "Must have a URI");
  NS_PRECONDITION(aRequestingNode, "Must have a node");

  nsCOMPtr<nsILoadGroup> loadGroup =
    aRequestingNode->OwnerDoc()->GetDocumentLoadGroup();

  nsresult rv = NS_OK;
  nsCOMPtr<nsIChannel> channel;
  rv = NS_NewChannel(getter_AddRefs(channel),
                     aURI,
                     aRequestingNode,
                     nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_INHERITS,
                     nsIContentPolicy::TYPE_OTHER,
                     loadGroup);
  NS_ENSURE_SUCCESS(rv, rv);

  mURI = aURI;

  return channel->AsyncOpen2(this);
}

NS_IMPL_ISUPPORTS(nsExternalResourceMap::LoadgroupCallbacks,
                  nsIInterfaceRequestor)

#define IMPL_SHIM(_i) \
  NS_IMPL_ISUPPORTS(nsExternalResourceMap::LoadgroupCallbacks::_i##Shim, _i)

IMPL_SHIM(nsILoadContext)
IMPL_SHIM(nsIProgressEventSink)
IMPL_SHIM(nsIChannelEventSink)
IMPL_SHIM(nsISecurityEventSink)
IMPL_SHIM(nsIApplicationCacheContainer)

#undef IMPL_SHIM

#define IID_IS(_i) aIID.Equals(NS_GET_IID(_i))

#define TRY_SHIM(_i)                                                       \
  PR_BEGIN_MACRO                                                           \
    if (IID_IS(_i)) {                                                      \
      nsCOMPtr<_i> real = do_GetInterface(mCallbacks);                     \
      if (!real) {                                                         \
        return NS_NOINTERFACE;                                             \
      }                                                                    \
      nsCOMPtr<_i> shim = new _i##Shim(this, real);                        \
      shim.forget(aSink);                                                  \
      return NS_OK;                                                        \
    }                                                                      \
  PR_END_MACRO

NS_IMETHODIMP
nsExternalResourceMap::LoadgroupCallbacks::GetInterface(const nsIID & aIID,
                                                        void **aSink)
{
  if (mCallbacks &&
      (IID_IS(nsIPrompt) || IID_IS(nsIAuthPrompt) || IID_IS(nsIAuthPrompt2) ||
       IID_IS(nsITabChild))) {
    return mCallbacks->GetInterface(aIID, aSink);
  }

  *aSink = nullptr;

  TRY_SHIM(nsILoadContext);
  TRY_SHIM(nsIProgressEventSink);
  TRY_SHIM(nsIChannelEventSink);
  TRY_SHIM(nsISecurityEventSink);
  TRY_SHIM(nsIApplicationCacheContainer);

  return NS_NOINTERFACE;
}

#undef TRY_SHIM
#undef IID_IS

nsExternalResourceMap::ExternalResource::~ExternalResource()
{
  if (mViewer) {
    mViewer->Close(nullptr);
    mViewer->Destroy();
  }
}

// ==================================================================
// =
// ==================================================================

// If we ever have an nsIDocumentObserver notification for stylesheet title
// changes we should update the list from that instead of overriding
// EnsureFresh.
class nsDOMStyleSheetSetList final : public DOMStringList
{
public:
  explicit nsDOMStyleSheetSetList(nsIDocument* aDocument);

  void Disconnect()
  {
    mDocument = nullptr;
  }

  virtual void EnsureFresh() override;

protected:
  nsIDocument* mDocument;  // Our document; weak ref.  It'll let us know if it
                           // dies.
};

nsDOMStyleSheetSetList::nsDOMStyleSheetSetList(nsIDocument* aDocument)
  : mDocument(aDocument)
{
  NS_ASSERTION(mDocument, "Must have document!");
}

void
nsDOMStyleSheetSetList::EnsureFresh()
{
  MOZ_ASSERT(NS_IsMainThread());

  mNames.Clear();

  if (!mDocument) {
    return; // Spec says "no exceptions", and we have no style sets if we have
            // no document, for sure
  }

  int32_t count = mDocument->GetNumberOfStyleSheets();
  nsAutoString title;
  for (int32_t index = 0; index < count; index++) {
    StyleSheet* sheet = mDocument->GetStyleSheetAt(index);
    NS_ASSERTION(sheet, "Null sheet in sheet list!");
    sheet->GetTitle(title);
    if (!title.IsEmpty() && !mNames.Contains(title) && !Add(title)) {
      return;
    }
  }
}

// ==================================================================
nsIDocument::SelectorCache::SelectorCache(nsIEventTarget* aEventTarget)
  : nsExpirationTracker<SelectorCacheKey, 4>(
      1000, "nsIDocument::SelectorCache", aEventTarget)
{ }

nsIDocument::SelectorCache::~SelectorCache()
{
  AgeAllGenerations();
}

// CacheList takes ownership of aSelectorList.
void nsIDocument::SelectorCache::CacheList(const nsAString& aSelector,
                                           nsCSSSelectorList* aSelectorList)
{
  MOZ_ASSERT(NS_IsMainThread());
  SelectorCacheKey* key = new SelectorCacheKey(aSelector);
  mTable.Put(key->mKey, aSelectorList);
  AddObject(key);
}

void nsIDocument::SelectorCache::NotifyExpired(SelectorCacheKey* aSelector)
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aSelector);

  // There is no guarantee that this method won't be re-entered when selector
  // matching is ongoing because "memory-pressure" could be notified immediately
  // when OOM happens according to the design of nsExpirationTracker.
  // The perfect solution is to delete the |aSelector| and its nsCSSSelectorList
  // in mTable asynchronously.
  // We remove these objects synchronously for now because NotifiyExpired() will
  // never be triggered by "memory-pressure" which is not implemented yet in
  // the stage 2 of mozalloc_handle_oom().
  // Once these objects are removed asynchronously, we should update the warning
  // added in mozalloc_handle_oom() as well.
  RemoveObject(aSelector);
  mTable.Remove(aSelector->mKey);
  delete aSelector;
}

struct nsIDocument::FrameRequest
{
  FrameRequest(FrameRequestCallback& aCallback,
               int32_t aHandle) :
    mCallback(&aCallback),
    mHandle(aHandle)
  {}

  // Conversion operator so that we can append these to a
  // FrameRequestCallbackList
  operator const RefPtr<FrameRequestCallback>& () const {
    return mCallback;
  }

  // Comparator operators to allow RemoveElementSorted with an
  // integer argument on arrays of FrameRequest
  bool operator==(int32_t aHandle) const {
    return mHandle == aHandle;
  }
  bool operator<(int32_t aHandle) const {
    return mHandle < aHandle;
  }

  RefPtr<FrameRequestCallback> mCallback;
  int32_t mHandle;
};

static already_AddRefed<mozilla::dom::NodeInfo> nullNodeInfo;

// ==================================================================
// =
// ==================================================================
nsIDocument::nsIDocument()
  : nsINode(nullNodeInfo),
    mReferrerPolicySet(false),
    mReferrerPolicy(mozilla::net::RP_Unset),
    mBlockAllMixedContent(false),
    mBlockAllMixedContentPreloads(false),
    mUpgradeInsecureRequests(false),
    mUpgradeInsecurePreloads(false),
    mCharacterSet(WINDOWS_1252_ENCODING),
    mCharacterSetSource(0),
    mParentDocument(nullptr),
    mCachedRootElement(nullptr),
    mNodeInfoManager(nullptr),
    mBidiEnabled(false),
    mMathMLEnabled(false),
    mIsInitialDocumentInWindow(false),
    mIgnoreDocGroupMismatches(false),
    mLoadedAsData(false),
    mLoadedAsInteractiveData(false),
    mMayStartLayout(true),
    mHaveFiredTitleChange(false),
    mIsShowing(false),
    mVisible(true),
    mHasReferrerPolicyCSP(false),
    mRemovedFromDocShell(false),
    // mAllowDNSPrefetch starts true, so that we can always reliably && it
    // with various values that might disable it.  Since we never prefetch
    // unless we get a window, and in that case the docshell value will get
    // &&-ed in, this is safe.
    mAllowDNSPrefetch(true),
    mIsStaticDocument(false),
    mCreatingStaticClone(false),
    mInUnlinkOrDeletion(false),
    mHasHadScriptHandlingObject(false),
    mIsBeingUsedAsImage(false),
    mIsSyntheticDocument(false),
    mHasLinksToUpdate(false),
    mHasLinksToUpdateRunnable(false),
    mMayHaveDOMMutationObservers(false),
    mMayHaveAnimationObservers(false),
    mHasMixedActiveContentLoaded(false),
    mHasMixedActiveContentBlocked(false),
    mHasMixedDisplayContentLoaded(false),
    mHasMixedDisplayContentBlocked(false),
    mHasMixedContentObjectSubrequest(false),
    mHasCSP(false),
    mHasUnsafeEvalCSP(false),
    mHasUnsafeInlineCSP(false),
    mHasTrackingContentBlocked(false),
    mHasTrackingContentLoaded(false),
    mBFCacheDisallowed(false),
    mHasHadDefaultView(false),
    mStyleSheetChangeEventsEnabled(false),
    mIsSrcdocDocument(false),
    mDidDocumentOpen(false),
    mHasDisplayDocument(false),
    mFontFaceSetDirty(true),
    mGetUserFontSetCalled(false),
    mPostedFlushUserFontSet(false),
    mDidFireDOMContentLoaded(true),
    mHasScrollLinkedEffect(false),
    mFrameRequestCallbacksScheduled(false),
    mIsTopLevelContentDocument(false),
    mIsContentDocument(false),
    mMightHaveStaleServoData(false),
    mDidCallBeginLoad(false),
    mBufferingCSPViolations(false),
    mIsScopedStyleEnabled(eScopedStyle_Unknown),
    mCompatMode(eCompatibility_FullStandards),
    mReadyState(ReadyState::READYSTATE_UNINITIALIZED),
    mStyleBackendType(StyleBackendType::None),
#ifdef MOZILLA_INTERNAL_API
    mVisibilityState(dom::VisibilityState::Hidden),
#else
    mDummy(0),
#endif
    mType(eUnknown),
    mDefaultElementType(0),
    mAllowXULXBL(eTriUnset),
#ifdef DEBUG
    mIsLinkUpdateRegistrationsForbidden(false),
#endif
    mBidiOptions(IBMBIDI_DEFAULT_BIDI_OPTIONS),
    mSandboxFlags(0),
    mPartID(0),
    mMarkedCCGeneration(0),
    mPresShell(nullptr),
    mSubtreeModifiedDepth(0),
    mEventsSuppressed(0),
    mExternalScriptsBeingEvaluated(0),
    mFrameRequestCallbackCounter(0),
    mStaticCloneCount(0),
    mWindow(nullptr),
    mBFCacheEntry(nullptr),
    mInSyncOperationCount(0),
    mBlockDOMContentLoaded(0),
    mUseCounters(0),
    mChildDocumentUseCounters(0),
    mNotifiedPageForUseCounter(0),
    mIncCounters(),
    mUserHasInteracted(false),
    mServoRestyleRootDirtyBits(0)
{
  SetIsInDocument();
  for (auto& cnt : mIncCounters) {
    cnt = 0;
  }
}

nsDocument::nsDocument(const char* aContentType)
  : nsIDocument()
  , mSubDocuments(nullptr)
  , mFlashClassification(FlashClassification::Unclassified)
  , mHeaderData(nullptr)
  , mIsGoingAway(false)
  , mInDestructor(false)
  , mMayHaveTitleElement(false)
  , mHasWarnedAboutBoxObjects(false)
  , mDelayFrameLoaderInitialization(false)
  , mSynchronousDOMContentLoaded(false)
  , mInXBLUpdate(false)
  , mParserAborted(false)
  , mCurrentOrientationAngle(0)
  , mCurrentOrientationType(OrientationType::Portrait_primary)
  , mSSApplicableStateNotificationPending(false)
  , mReportedUseCounters(false)
  , mStyleSetFilled(false)
  , mPendingFullscreenRequests(0)
  , mXMLDeclarationBits(0)
  , mBoxObjectTable(nullptr)
  , mUpdateNestLevel(0)
  , mOnloadBlockCount(0)
  , mAsyncOnloadBlockCount(0)
#ifdef DEBUG
  , mStyledLinksCleared(false)
#endif
  , mPreloadPictureDepth(0)
  , mScrolledToRefAlready(0)
  , mChangeScrollPosWhenScrollingToRef(0)
  , mViewportType(Unknown)
  , mValidWidth(false)
  , mValidHeight(false)
  , mAutoSize(false)
  , mAllowZoom(false)
  , mAllowDoubleTapZoom(false)
  , mValidScaleFloat(false)
  , mValidMaxScale(false)
  , mScaleStrEmpty(false)
  , mWidthStrEmpty(false)
  , mStackRefCnt(0)
  , mNeedsReleaseAfterStackRefCntRelease(false)
  , mMaybeServiceWorkerControlled(false)
#ifdef DEBUG
  , mWillReparent(false)
#endif
  , mDOMLoadingSet(false)
  , mDOMInteractiveSet(false)
  , mDOMCompleteSet(false)
{
  SetContentTypeInternal(nsDependentCString(aContentType));

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p created", this));

  // Start out mLastStyleSheetSet as null, per spec
  SetDOMStringToNull(mLastStyleSheetSet);

  // void state used to differentiate an empty source from an unselected source
  mPreloadPictureFoundSource.SetIsVoid(true);
  // For determining if this is a flash document which should be
  // blocked based on its principal.
  mPrincipalFlashClassifier = new PrincipalFlashClassifier();
}

void
nsDocument::ClearAllBoxObjects()
{
  if (mBoxObjectTable) {
    for (auto iter = mBoxObjectTable->Iter(); !iter.Done(); iter.Next()) {
      nsPIBoxObject* boxObject = iter.UserData();
      if (boxObject) {
        boxObject->Clear();
      }
    }
    delete mBoxObjectTable;
    mBoxObjectTable = nullptr;
  }
}

nsIDocument::~nsIDocument()
{
  MOZ_ASSERT(mDOMMediaQueryLists.isEmpty(),
             "must not have media query lists left");

  if (mNodeInfoManager) {
    mNodeInfoManager->DropDocumentReference();
  }

  if (mDocGroup) {
    mDocGroup->RemoveDocument(this);
  }

  UnlinkOriginalDocumentIfStatic();
}

bool
nsDocument::IsAboutPage() const
{
  nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
  nsCOMPtr<nsIURI> uri;
  principal->GetURI(getter_AddRefs(uri));
  bool isAboutScheme = true;
  if (uri) {
    uri->SchemeIs("about", &isAboutScheme);
  }
  return isAboutScheme;
}

nsDocument::~nsDocument()
{
  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p destroyed", this));

  NS_ASSERTION(!mIsShowing, "Destroying a currently-showing document");

  if (IsTopLevelContentDocument()) {
    //don't report for about: pages
    if (!IsAboutPage()) {
      // Record the page load
      uint32_t pageLoaded = 1;
      Accumulate(Telemetry::MIXED_CONTENT_UNBLOCK_COUNTER, pageLoaded);
      // Record the mixed content status of the docshell in Telemetry
      enum {
        NO_MIXED_CONTENT = 0, // There is no Mixed Content on the page
        MIXED_DISPLAY_CONTENT = 1, // The page attempted to load Mixed Display Content
        MIXED_ACTIVE_CONTENT = 2, // The page attempted to load Mixed Active Content
        MIXED_DISPLAY_AND_ACTIVE_CONTENT = 3 // The page attempted to load Mixed Display & Mixed Active Content
      };

      bool mixedActiveLoaded = GetHasMixedActiveContentLoaded();
      bool mixedActiveBlocked = GetHasMixedActiveContentBlocked();

      bool mixedDisplayLoaded = GetHasMixedDisplayContentLoaded();
      bool mixedDisplayBlocked = GetHasMixedDisplayContentBlocked();

      bool hasMixedDisplay = (mixedDisplayBlocked || mixedDisplayLoaded);
      bool hasMixedActive = (mixedActiveBlocked || mixedActiveLoaded);

      uint32_t mixedContentLevel = NO_MIXED_CONTENT;
      if (hasMixedDisplay && hasMixedActive) {
        mixedContentLevel = MIXED_DISPLAY_AND_ACTIVE_CONTENT;
      } else if (hasMixedActive){
        mixedContentLevel = MIXED_ACTIVE_CONTENT;
      } else if (hasMixedDisplay) {
        mixedContentLevel = MIXED_DISPLAY_CONTENT;
      }
      Accumulate(Telemetry::MIXED_CONTENT_PAGE_LOAD, mixedContentLevel);

      // record mixed object subrequest telemetry
      if (mHasMixedContentObjectSubrequest) {
        /* mixed object subrequest loaded on page*/
        Accumulate(Telemetry::MIXED_CONTENT_OBJECT_SUBREQUEST, 1);
      } else {
        /* no mixed object subrequests loaded on page*/
        Accumulate(Telemetry::MIXED_CONTENT_OBJECT_SUBREQUEST, 0);
      }

      // record CSP telemetry on this document
      if (mHasCSP) {
        Accumulate(Telemetry::CSP_DOCUMENTS_COUNT, 1);
        Accumulate(Telemetry::CSP_REFERRER_DIRECTIVE, mHasReferrerPolicyCSP);
      }
      if (mHasUnsafeInlineCSP) {
        Accumulate(Telemetry::CSP_UNSAFE_INLINE_DOCUMENTS_COUNT, 1);
      }
      if (mHasUnsafeEvalCSP) {
        Accumulate(Telemetry::CSP_UNSAFE_EVAL_DOCUMENTS_COUNT, 1);
      }
    }
  }

  ReportUseCounters();

  mInDestructor = true;
  mInUnlinkOrDeletion = true;

  mozilla::DropJSObjects(this);

  // Clear mObservers to keep it in sync with the mutationobserver list
  mObservers.Clear();

  mIntersectionObservers.Clear();

  if (mStyleSheetSetList) {
    mStyleSheetSetList->Disconnect();
  }

  if (mAnimationController) {
    mAnimationController->Disconnect();
  }

  MOZ_ASSERT(mTimelines.isEmpty());

  mParentDocument = nullptr;

  // Kill the subdocument map, doing this will release its strong
  // references, if any.
  delete mSubDocuments;
  mSubDocuments = nullptr;

  // Destroy link map now so we don't waste time removing
  // links one by one
  DestroyElementMaps();

  nsAutoScriptBlocker scriptBlocker;

  for (uint32_t indx = mChildren.ChildCount(); indx-- != 0; ) {
    mChildren.ChildAt(indx)->UnbindFromTree();
    mChildren.RemoveChildAt(indx);
  }
  mFirstChild = nullptr;
  mCachedRootElement = nullptr;

  // Let the stylesheets know we're going away
  for (StyleSheet* sheet : mStyleSheets) {
    sheet->ClearAssociatedDocument();
  }
  for (auto& sheets : mAdditionalSheets) {
    for (StyleSheet* sheet : sheets) {
      sheet->ClearAssociatedDocument();
    }
  }
  if (mAttrStyleSheet) {
    mAttrStyleSheet->SetOwningDocument(nullptr);
  }
  // We don't own the mOnDemandBuiltInUASheets, so we don't need to reset them.

  if (mListenerManager) {
    mListenerManager->Disconnect();
    UnsetFlags(NODE_HAS_LISTENERMANAGER);
  }

  if (mScriptLoader) {
    mScriptLoader->DropDocumentReference();
  }

  if (mCSSLoader) {
    // Could be null here if Init() failed or if we have been unlinked.
    mCSSLoader->DropDocumentReference();
  }

  if (mStyleImageLoader) {
    mStyleImageLoader->DropDocumentReference();
  }

  delete mHeaderData;

  ClearAllBoxObjects();

  mPendingTitleChangeEvent.Revoke();

  mPlugins.Clear();
}

NS_INTERFACE_TABLE_HEAD(nsDocument)
  NS_WRAPPERCACHE_INTERFACE_TABLE_ENTRY
  NS_INTERFACE_TABLE_BEGIN
    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsDocument, nsISupports, nsINode)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsINode)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDocument)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMDocument)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMNode)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMDocumentXBL)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIScriptObjectPrincipal)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMEventTarget)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, mozilla::dom::EventTarget)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsISupportsWeakReference)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIRadioGroupContainer)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIMutationObserver)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIApplicationCacheContainer)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIObserver)
    NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMXPathEvaluator)
  NS_INTERFACE_TABLE_END
  NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(nsDocument)
NS_INTERFACE_MAP_END


NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDocument)
NS_IMETHODIMP_(MozExternalRefCountType)
nsDocument::Release()
{
  NS_PRECONDITION(0 != mRefCnt, "dup release");
  NS_ASSERT_OWNINGTHREAD(nsDocument);
  nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(nsDocument)::Upcast(this);
  bool shouldDelete = false;
  nsrefcnt count = mRefCnt.decr(base, &shouldDelete);
  NS_LOG_RELEASE(this, count, "nsDocument");
  if (count == 0) {
    if (mStackRefCnt && !mNeedsReleaseAfterStackRefCntRelease) {
      mNeedsReleaseAfterStackRefCntRelease = true;
      NS_ADDREF_THIS();
      return mRefCnt.get();
    }
    mRefCnt.incr(base);
    nsNodeUtils::LastRelease(this);
    mRefCnt.decr(base);
    if (shouldDelete) {
      mRefCnt.stabilizeForDeletion();
      DeleteCycleCollectable();
    }
  }
  return count;
}

NS_IMETHODIMP_(void)
nsDocument::DeleteCycleCollectable()
{
  delete this;
}

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsDocument)
  if (Element::CanSkip(tmp, aRemovingAllowed)) {
    EventListenerManager* elm = tmp->GetExistingListenerManager();
    if (elm) {
      elm->MarkForCC();
    }
    return true;
  }
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsDocument)
  return Element::CanSkipInCC(tmp);
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsDocument)
  return Element::CanSkipThis(tmp);
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END

static const char* kNSURIs[] = {
  "([none])",
  "(xmlns)",
  "(xml)",
  "(xhtml)",
  "(XLink)",
  "(XSLT)",
  "(XBL)",
  "(MathML)",
  "(RDF)",
  "(XUL)"
};

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsDocument)
  if (MOZ_UNLIKELY(cb.WantDebugInfo())) {
    char name[512];
    nsAutoCString loadedAsData;
    if (tmp->IsLoadedAsData()) {
      loadedAsData.AssignLiteral("data");
    } else {
      loadedAsData.AssignLiteral("normal");
    }
    uint32_t nsid = tmp->GetDefaultNamespaceID();
    nsAutoCString uri;
    if (tmp->mDocumentURI)
      uri = tmp->mDocumentURI->GetSpecOrDefault();
    if (nsid < ArrayLength(kNSURIs)) {
      SprintfLiteral(name, "nsDocument %s %s %s",
                     loadedAsData.get(), kNSURIs[nsid], uri.get());
    }
    else {
      SprintfLiteral(name, "nsDocument %s %s",
                     loadedAsData.get(), uri.get());
    }
    cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name);
  }
  else {
    NS_IMPL_CYCLE_COLLECTION_DESCRIBE(nsDocument, tmp->mRefCnt.get())
  }

  if (!nsINode::Traverse(tmp, cb)) {
    return NS_SUCCESS_INTERRUPTED_TRAVERSE;
  }

  if (tmp->mMaybeEndOutermostXBLUpdateRunner) {
    // The cached runnable keeps a reference to the document object..
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb,
                                       "mMaybeEndOutermostXBLUpdateRunner.mObj");
    cb.NoteXPCOMChild(ToSupports(tmp));
  }

  for (auto iter = tmp->mIdentifierMap.ConstIter(); !iter.Done();
       iter.Next()) {
    iter.Get()->Traverse(&cb);
  }

  tmp->mExternalResourceMap.Traverse(&cb);

  // Traverse the mChildren nsAttrAndChildArray.
  for (int32_t indx = int32_t(tmp->mChildren.ChildCount()); indx > 0; --indx) {
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mChildren[i]");
    cb.NoteXPCOMChild(tmp->mChildren.ChildAt(indx - 1));
  }

  // Traverse all nsIDocument pointer members.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSecurityInfo)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDisplayDocument)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFontFaceSet)

  // Traverse all nsDocument nsCOMPtrs.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParser)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mScriptGlobalObject)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mListenerManager)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDOMStyleSheets)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheetSetList)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mScriptLoader)

  for (auto iter = tmp->mRadioGroups.Iter(); !iter.Done(); iter.Next()) {
    nsRadioGroupStruct* radioGroup = iter.UserData();
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(
      cb, "mRadioGroups entry->mSelectedRadioButton");
    cb.NoteXPCOMChild(ToSupports(radioGroup->mSelectedRadioButton));

    uint32_t i, count = radioGroup->mRadioButtons.Count();
    for (i = 0; i < count; ++i) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(
        cb, "mRadioGroups entry->mRadioButtons[i]");
      cb.NoteXPCOMChild(radioGroup->mRadioButtons[i]);
    }
  }

  // The boxobject for an element will only exist as long as it's in the
  // document, so we'll traverse the table here instead of from the element.
  if (tmp->mBoxObjectTable) {
    for (auto iter = tmp->mBoxObjectTable->Iter(); !iter.Done(); iter.Next()) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mBoxObjectTable entry");
      cb.NoteXPCOMChild(iter.UserData());
    }
  }

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChannel)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleAttrStyleSheet)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mXPathEvaluator)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLayoutHistoryState)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOnloadBlocker)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFirstBaseNodeWithHref)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDOMImplementation)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mImageMaps)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOrientationPendingPromise)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOriginalDocument)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCachedEncoder)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStateObjectCached)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocumentTimeline)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPendingAnimationTracker)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTemplateContentsOwner)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChildrenCollection)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAnonymousContents)

  // Traverse all our nsCOMArrays.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheets)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOnDemandBuiltInUASheets)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPreloadingImages)

  for (uint32_t i = 0; i < tmp->mFrameRequestCallbacks.Length(); ++i) {
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mFrameRequestCallbacks[i]");
    cb.NoteXPCOMChild(tmp->mFrameRequestCallbacks[i].mCallback);
  }

  // Traverse animation components
  if (tmp->mAnimationController) {
    tmp->mAnimationController->Traverse(&cb);
  }

  if (tmp->mSubDocuments) {
    for (auto iter = tmp->mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
      auto entry = static_cast<SubDocMapEntry*>(iter.Get());

      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb,
                                         "mSubDocuments entry->mKey");
      cb.NoteXPCOMChild(entry->mKey);
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb,
                                         "mSubDocuments entry->mSubDocument");
      cb.NoteXPCOMChild(entry->mSubDocument);
    }
  }

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCSSLoader)

  // We own only the items in mDOMMediaQueryLists that have listeners;
  // this reference is managed by their AddListener and RemoveListener
  // methods.
  for (auto mql : tmp->mDOMMediaQueryLists) {
    if (mql->HasListeners()) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mDOMMediaQueryLists item");
      cb.NoteXPCOMChild(mql);
    }
  }
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_CLASS(nsDocument)

NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(nsDocument)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsDocument)
  tmp->mInUnlinkOrDeletion = true;

  // Clear out our external resources
  tmp->mExternalResourceMap.Shutdown();

  nsAutoScriptBlocker scriptBlocker;

  nsINode::Unlink(tmp);

  // Unlink the mChildren nsAttrAndChildArray.
  uint32_t childCount = tmp->mChildren.ChildCount();
  if (childCount) {
    while (childCount-- > 0) {
      // Hold a strong ref to the node when we remove it, because we may be
      // the last reference to it.  We need to call TakeChildAt() and
      // update mFirstChild before calling UnbindFromTree, since this last
      // can notify various observers and they should really see consistent
      // tree state.
      // If this code changes, change the corresponding code in
      // FragmentOrElement's unlink impl and ContentUnbinder::UnbindSubtree.
      nsCOMPtr<nsIContent> child = tmp->mChildren.TakeChildAt(childCount);
      if (childCount == 0) {
        tmp->mFirstChild = nullptr;
      }
      child->UnbindFromTree();
    }
  }
  tmp->mFirstChild = nullptr;

  tmp->UnlinkOriginalDocumentIfStatic();

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mXPathEvaluator)
  tmp->mCachedRootElement = nullptr; // Avoid a dangling pointer
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDisplayDocument)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFirstBaseNodeWithHref)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mMaybeEndOutermostXBLUpdateRunner)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDOMImplementation)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mImageMaps)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCachedEncoder)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocumentTimeline)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPendingAnimationTracker)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mTemplateContentsOwner)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mChildrenCollection)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOrientationPendingPromise)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFontFaceSet)

  tmp->mParentDocument = nullptr;

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPreloadingImages)

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mIntersectionObservers)

  tmp->ClearAllBoxObjects();

  if (tmp->mListenerManager) {
    tmp->mListenerManager->Disconnect();
    tmp->UnsetFlags(NODE_HAS_LISTENERMANAGER);
    tmp->mListenerManager = nullptr;
  }

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDOMStyleSheets)

  if (tmp->mStyleSheetSetList) {
    tmp->mStyleSheetSetList->Disconnect();
    tmp->mStyleSheetSetList = nullptr;
  }

  delete tmp->mSubDocuments;
  tmp->mSubDocuments = nullptr;

  tmp->mFrameRequestCallbacks.Clear();
  MOZ_RELEASE_ASSERT(!tmp->mFrameRequestCallbacksScheduled,
                     "How did we get here without our presshell going away "
                     "first?");

  tmp->mRadioGroups.Clear();

  // nsDocument has a pretty complex destructor, so we're going to
  // assume that *most* cycles you actually want to break somewhere
  // else, and not unlink an awful lot here.

  tmp->mIdentifierMap.Clear();
  tmp->mExpandoAndGeneration.OwnerUnlinked();

  if (tmp->mAnimationController) {
    tmp->mAnimationController->Unlink();
  }

  tmp->mPendingTitleChangeEvent.Revoke();

  if (tmp->mCSSLoader) {
    tmp->mCSSLoader->DropDocumentReference();
    NS_IMPL_CYCLE_COLLECTION_UNLINK(mCSSLoader)
  }

  // We own only the items in mDOMMediaQueryLists that have listeners;
  // this reference is managed by their AddListener and RemoveListener
  // methods.
  for (MediaQueryList* mql = tmp->mDOMMediaQueryLists.getFirst(); mql;) {
    MediaQueryList* next = mql->getNext();
    mql->Disconnect();
    mql = next;
  }

  tmp->mInUnlinkOrDeletion = false;
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

nsresult
nsDocument::Init()
{
  if (mCSSLoader || mStyleImageLoader || mNodeInfoManager || mScriptLoader) {
    return NS_ERROR_ALREADY_INITIALIZED;
  }

  // Force initialization.
  nsINode::nsSlots* slots = Slots();

  // Prepend self as mutation-observer whether we need it or not (some
  // subclasses currently do, other don't). This is because the code in
  // nsNodeUtils always notifies the first observer first, expecting the
  // first observer to be the document.
  NS_ENSURE_TRUE(slots->mMutationObservers.PrependElementUnlessExists(static_cast<nsIMutationObserver*>(this)),
                 NS_ERROR_OUT_OF_MEMORY);


  mOnloadBlocker = new nsOnloadBlocker();
  mCSSLoader = new mozilla::css::Loader(this);
  // Assume we're not quirky, until we know otherwise
  mCSSLoader->SetCompatibilityMode(eCompatibility_FullStandards);

  mStyleImageLoader = new mozilla::css::ImageLoader(this);

  mNodeInfoManager = new nsNodeInfoManager();
  nsresult rv = mNodeInfoManager->Init(this);
  NS_ENSURE_SUCCESS(rv, rv);

  // mNodeInfo keeps NodeInfoManager alive!
  mNodeInfo = mNodeInfoManager->GetDocumentNodeInfo();
  NS_ENSURE_TRUE(mNodeInfo, NS_ERROR_OUT_OF_MEMORY);
  MOZ_ASSERT(mNodeInfo->NodeType() == nsIDOMNode::DOCUMENT_NODE,
             "Bad NodeType in aNodeInfo");

  NS_ASSERTION(OwnerDoc() == this, "Our nodeinfo is busted!");

  // If after creation the owner js global is not set for a document
  // we use the default compartment for this document, instead of creating
  // wrapper in some random compartment when the document is exposed to js
  // via some events.
  nsCOMPtr<nsIGlobalObject> global = xpc::NativeGlobal(xpc::PrivilegedJunkScope());
  NS_ENSURE_TRUE(global, NS_ERROR_FAILURE);
  mScopeObject = do_GetWeakReference(global);
  MOZ_ASSERT(mScopeObject);

  mScriptLoader = new dom::ScriptLoader(this);

  mozilla::HoldJSObjects(this);

  return NS_OK;
}

void
nsIDocument::DeleteAllProperties()
{
  for (uint32_t i = 0; i < GetPropertyTableCount(); ++i) {
    PropertyTable(i)->DeleteAllProperties();
  }
}

void
nsIDocument::DeleteAllPropertiesFor(nsINode* aNode)
{
  for (uint32_t i = 0; i < GetPropertyTableCount(); ++i) {
    PropertyTable(i)->DeleteAllPropertiesFor(aNode);
  }
}

nsPropertyTable*
nsIDocument::GetExtraPropertyTable(uint16_t aCategory)
{
  NS_ASSERTION(aCategory > 0, "Category 0 should have already been handled");
  while (aCategory >= mExtraPropertyTables.Length() + 1) {
    mExtraPropertyTables.AppendElement(new nsPropertyTable());
  }
  return mExtraPropertyTables[aCategory - 1];
}

bool
nsIDocument::IsVisibleConsideringAncestors() const
{
  const nsIDocument *parent = this;
  do {
    if (!parent->IsVisible()) {
      return false;
    }
  } while ((parent = parent->GetParentDocument()));

  return true;
      }

void
nsDocument::Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup)
{
  nsCOMPtr<nsIURI> uri;
  nsCOMPtr<nsIPrincipal> principal;
  if (aChannel) {
    // Note: this code is duplicated in XULDocument::StartDocumentLoad and
    // nsScriptSecurityManager::GetChannelResultPrincipal.
    // Note: this should match nsDocShell::OnLoadingSite
    NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));

    nsIScriptSecurityManager *securityManager =
      nsContentUtils::GetSecurityManager();
    if (securityManager) {
      securityManager->GetChannelResultPrincipal(aChannel,
                                                 getter_AddRefs(principal));
    }
  }

  principal = MaybeDowngradePrincipal(principal);

  ResetToURI(uri, aLoadGroup, principal);

  // Note that, since mTiming does not change during a reset, the
  // navigationStart time remains unchanged and therefore any future new
  // timeline will have the same global clock time as the old one.
  mDocumentTimeline = nullptr;

  nsCOMPtr<nsIPropertyBag2> bag = do_QueryInterface(aChannel);
  if (bag) {
    nsCOMPtr<nsIURI> baseURI;
    bag->GetPropertyAsInterface(NS_LITERAL_STRING("baseURI"),
                                NS_GET_IID(nsIURI), getter_AddRefs(baseURI));
    if (baseURI) {
      mDocumentBaseURI = baseURI;
      mChromeXHRDocBaseURI = nullptr;
    }
  }

  mChannel = aChannel;
}

void
nsDocument::ResetToURI(nsIURI *aURI, nsILoadGroup *aLoadGroup,
                       nsIPrincipal* aPrincipal)
{
  NS_PRECONDITION(aURI, "Null URI passed to ResetToURI");

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
          ("DOCUMENT %p ResetToURI %s", this, aURI->GetSpecOrDefault().get()));

  mSecurityInfo = nullptr;

  mDocumentLoadGroup = nullptr;

  // Delete references to sub-documents and kill the subdocument map,
  // if any. It holds strong references
  delete mSubDocuments;
  mSubDocuments = nullptr;

  // Destroy link map now so we don't waste time removing
  // links one by one
  DestroyElementMaps();

  bool oldVal = mInUnlinkOrDeletion;
  mInUnlinkOrDeletion = true;
  uint32_t count = mChildren.ChildCount();
  { // Scope for update
    MOZ_AUTO_DOC_UPDATE(this, UPDATE_CONTENT_MODEL, true);
    for (int32_t i = int32_t(count) - 1; i >= 0; i--) {
      nsCOMPtr<nsIContent> content = mChildren.ChildAt(i);

      nsIContent* previousSibling = content->GetPreviousSibling();

      if (nsINode::GetFirstChild() == content) {
        mFirstChild = content->GetNextSibling();
      }
      mChildren.RemoveChildAt(i);
      if (content == mCachedRootElement) {
        // Immediately clear mCachedRootElement, now that it's been removed
        // from mChildren, so that GetRootElement() will stop returning this
        // now-stale value.
        mCachedRootElement = nullptr;
      }
      nsNodeUtils::ContentRemoved(this, content, i, previousSibling);
      content->UnbindFromTree();
    }
    MOZ_ASSERT(!mCachedRootElement,
               "After removing all children, there should be no root elem");
  }
  mInUnlinkOrDeletion = oldVal;

  // Reset our stylesheets
  ResetStylesheetsToURI(aURI);

  // Release the listener manager
  if (mListenerManager) {
    mListenerManager->Disconnect();
    mListenerManager = nullptr;
  }

  // Release the stylesheets list.
  mDOMStyleSheets = nullptr;

  // Release our principal after tearing down the document, rather than before.
  // This ensures that, during teardown, the document and the dying window (which
  // already nulled out its document pointer and cached the principal) have
  // matching principals.
  SetPrincipal(nullptr);

  // Clear the original URI so SetDocumentURI sets it.
  mOriginalURI = nullptr;

  SetDocumentURI(aURI);
  mChromeXHRDocURI = nullptr;
  // If mDocumentBaseURI is null, nsIDocument::GetBaseURI() returns
  // mDocumentURI.
  mDocumentBaseURI = nullptr;
  mChromeXHRDocBaseURI = nullptr;

  if (aLoadGroup) {
    mDocumentLoadGroup = do_GetWeakReference(aLoadGroup);
    // there was an assertion here that aLoadGroup was not null.  This
    // is no longer valid: nsDocShell::SetDocument does not create a
    // load group, and it works just fine

    // XXXbz what does "just fine" mean exactly?  And given that there
    // is no nsDocShell::SetDocument, what is this talking about?

    // Inform the associated request context about this load start so
    // any of its internal load progress flags gets reset.
    nsCOMPtr<nsIRequestContextService> rcsvc =
      do_GetService("@mozilla.org/network/request-context-service;1");
    if (rcsvc) {
      nsCOMPtr<nsIRequestContext> rc;
      rcsvc->GetRequestContextFromLoadGroup(aLoadGroup, getter_AddRefs(rc));
      if (rc) {
        rc->BeginLoad();
      }
    }
  }

  mLastModified.Truncate();
  // XXXbz I guess we're assuming that the caller will either pass in
  // a channel with a useful type or call SetContentType?
  SetContentTypeInternal(EmptyCString());
  mContentLanguage.Truncate();
  mBaseTarget.Truncate();
  mReferrer.Truncate();

  mXMLDeclarationBits = 0;

  // Now get our new principal
  if (aPrincipal) {
    SetPrincipal(aPrincipal);
  } else {
    nsIScriptSecurityManager *securityManager =
      nsContentUtils::GetSecurityManager();
    if (securityManager) {
      nsCOMPtr<nsILoadContext> loadContext(mDocumentContainer);

      if (!loadContext && aLoadGroup) {
        nsCOMPtr<nsIInterfaceRequestor> cbs;
        aLoadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));
        loadContext = do_GetInterface(cbs);
      }

      MOZ_ASSERT(loadContext,
                 "must have a load context or pass in an explicit principal");

      nsCOMPtr<nsIPrincipal> principal;
      nsresult rv = securityManager->
        GetLoadContextCodebasePrincipal(mDocumentURI, loadContext,
                                        getter_AddRefs(principal));
      if (NS_SUCCEEDED(rv)) {
        SetPrincipal(principal);
      }
    }
  }

  // Refresh the principal on the compartment.
  if (nsPIDOMWindowInner* win = GetInnerWindow()) {
    nsGlobalWindow::Cast(win)->RefreshCompartmentPrincipal();
  }
}

already_AddRefed<nsIPrincipal>
nsDocument::MaybeDowngradePrincipal(nsIPrincipal* aPrincipal)
{
  if (!aPrincipal) {
    return nullptr;
  }

  if (!sChromeInContentPrefCached) {
    sChromeInContentPrefCached = true;
    Preferences::AddBoolVarCache(&sChromeInContentAllowed,
                                 kChromeInContentPref, false);
  }
  if (!sChromeInContentAllowed &&
      nsContentUtils::IsSystemPrincipal(aPrincipal)) {
    // We basically want the parent document here, but because this is very
    // early in the load, GetParentDocument() returns null, so we use the
    // docshell hierarchy to get this information instead.
    if (mDocumentContainer) {
      nsCOMPtr<nsIDocShellTreeItem> parentDocShellItem;
      mDocumentContainer->GetParent(getter_AddRefs(parentDocShellItem));
      nsCOMPtr<nsIDocShell> parentDocShell = do_QueryInterface(parentDocShellItem);
      if (parentDocShell) {
        nsCOMPtr<nsIDocument> parentDoc;
        parentDoc = parentDocShell->GetDocument();
        if (!parentDoc ||
            !nsContentUtils::IsSystemPrincipal(parentDoc->NodePrincipal())) {
          nsCOMPtr<nsIPrincipal> nullPrincipal =
            do_CreateInstance("@mozilla.org/nullprincipal;1");
          return nullPrincipal.forget();
        }
      }
    }
  }
  nsCOMPtr<nsIPrincipal> principal(aPrincipal);
  return principal.forget();
}

void
nsDocument::RemoveDocStyleSheetsFromStyleSets()
{
  // The stylesheets should forget us
  for (StyleSheet* sheet : Reversed(mStyleSheets)) {
    sheet->ClearAssociatedDocument();

    if (sheet->IsApplicable()) {
      nsCOMPtr<nsIPresShell> shell = GetShell();
      if (shell) {
        shell->StyleSet()->RemoveDocStyleSheet(sheet);
      }
    }
    // XXX Tell observers?
  }
}

void
nsDocument::RemoveStyleSheetsFromStyleSets(
    const nsTArray<RefPtr<StyleSheet>>& aSheets,
    SheetType aType)
{
  // The stylesheets should forget us
  for (StyleSheet* sheet : Reversed(aSheets)) {
    sheet->ClearAssociatedDocument();

    if (sheet->IsApplicable()) {
      nsCOMPtr<nsIPresShell> shell = GetShell();
      if (shell) {
        shell->StyleSet()->RemoveStyleSheet(aType, sheet);
      }
    }
    // XXX Tell observers?
  }
}

void
nsDocument::ResetStylesheetsToURI(nsIURI* aURI)
{
  MOZ_ASSERT(aURI);

  mozAutoDocUpdate upd(this, UPDATE_STYLE, true);
  if (mStyleSetFilled) {
    // Skip removing style sheets from the style set if we know we haven't
    // filled the style set.  (This allows us to avoid calling
    // GetStyleBackendType() too early.)
    RemoveDocStyleSheetsFromStyleSets();
    RemoveStyleSheetsFromStyleSets(mOnDemandBuiltInUASheets, SheetType::Agent);
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eAgentSheet], SheetType::Agent);
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eUserSheet], SheetType::User);
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eAuthorSheet], SheetType::Doc);

    if (nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance()) {
      RemoveStyleSheetsFromStyleSets(
        *sheetService->AuthorStyleSheets(GetStyleBackendType()), SheetType::Doc);
    }

    mStyleSetFilled = false;
  }

  // Release all the sheets
  mStyleSheets.Clear();
  mOnDemandBuiltInUASheets.Clear();
  for (auto& sheets : mAdditionalSheets) {
    sheets.Clear();
  }

  // NOTE:  We don't release the catalog sheets.  It doesn't really matter
  // now, but it could in the future -- in which case not releasing them
  // is probably the right thing to do.

  // Now reset our inline style and attribute sheets.
  if (mAttrStyleSheet) {
    mAttrStyleSheet->Reset();
    mAttrStyleSheet->SetOwningDocument(this);
  } else {
    mAttrStyleSheet = new nsHTMLStyleSheet(this);
  }

  if (!mStyleAttrStyleSheet) {
    mStyleAttrStyleSheet = new nsHTMLCSSStyleSheet();
  }

  // Now set up our style sets
  nsCOMPtr<nsIPresShell> shell = GetShell();
  if (shell) {
    FillStyleSet(shell->StyleSet());
  }
}

static void
AppendSheetsToStyleSet(StyleSetHandle aStyleSet,
                       const nsTArray<RefPtr<StyleSheet>>& aSheets,
                       SheetType aType)
{
  for (StyleSheet* sheet : Reversed(aSheets)) {
    aStyleSet->AppendStyleSheet(aType, sheet);
  }
}


void
nsDocument::FillStyleSet(StyleSetHandle aStyleSet)
{
  NS_PRECONDITION(aStyleSet, "Must have a style set");
  NS_PRECONDITION(aStyleSet->SheetCount(SheetType::Doc) == 0,
                  "Style set already has document sheets?");

  MOZ_ASSERT(!mStyleSetFilled);

  for (StyleSheet* sheet : Reversed(mStyleSheets)) {
    if (sheet->IsApplicable()) {
      aStyleSet->AddDocStyleSheet(sheet, this);
    }
  }

  if (nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance()) {
    nsTArray<RefPtr<StyleSheet>>& sheets =
      *sheetService->AuthorStyleSheets(aStyleSet->BackendType());
    for (StyleSheet* sheet : sheets) {
      aStyleSet->AppendStyleSheet(SheetType::Doc, sheet);
    }
  }

  // Iterate backwards to maintain order
  for (StyleSheet* sheet : Reversed(mOnDemandBuiltInUASheets)) {
    if (sheet->IsApplicable()) {
      aStyleSet->PrependStyleSheet(SheetType::Agent, sheet);
    }
  }

  AppendSheetsToStyleSet(aStyleSet, mAdditionalSheets[eAgentSheet],
                         SheetType::Agent);
  AppendSheetsToStyleSet(aStyleSet, mAdditionalSheets[eUserSheet],
                         SheetType::User);
  AppendSheetsToStyleSet(aStyleSet, mAdditionalSheets[eAuthorSheet],
                         SheetType::Doc);

  mStyleSetFilled = true;
}

static void
WarnIfSandboxIneffective(nsIDocShell* aDocShell,
                         uint32_t aSandboxFlags,
                         nsIChannel* aChannel)
{
  // If the document is sandboxed (via the HTML5 iframe sandbox
  // attribute) and both the allow-scripts and allow-same-origin
  // keywords are supplied, the sandboxed document can call into its
  // parent document and remove its sandboxing entirely - we print a
  // warning to the web console in this case.
  if (aSandboxFlags & SANDBOXED_NAVIGATION &&
      !(aSandboxFlags & SANDBOXED_SCRIPTS) &&
      !(aSandboxFlags & SANDBOXED_ORIGIN)) {
    nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
    aDocShell->GetSameTypeParent(getter_AddRefs(parentAsItem));
    nsCOMPtr<nsIDocShell> parentDocShell = do_QueryInterface(parentAsItem);
    if (!parentDocShell) {
      return;
    }

    // Don't warn if our parent is not the top-level document.
    nsCOMPtr<nsIDocShellTreeItem> grandParentAsItem;
    parentDocShell->GetSameTypeParent(getter_AddRefs(grandParentAsItem));
    if (grandParentAsItem) {
      return;
    }

    nsCOMPtr<nsIChannel> parentChannel;
    parentDocShell->GetCurrentDocumentChannel(getter_AddRefs(parentChannel));
    if (!parentChannel) {
      return;
    }
    nsresult rv = nsContentUtils::CheckSameOrigin(aChannel, parentChannel);
    if (NS_FAILED(rv)) {
      return;
    }

    nsCOMPtr<nsIDocument> parentDocument = parentDocShell->GetDocument();
    nsCOMPtr<nsIURI> iframeUri;
    parentChannel->GetURI(getter_AddRefs(iframeUri));
    nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                    NS_LITERAL_CSTRING("Iframe Sandbox"),
                                    parentDocument,
                                    nsContentUtils::eSECURITY_PROPERTIES,
                                    "BothAllowScriptsAndSameOriginPresent",
                                    nullptr, 0, iframeUri);
  }
}

bool
nsDocument::IsSynthesized() {
  nsCOMPtr<nsIHttpChannelInternal> internalChan = do_QueryInterface(mChannel);
  bool synthesized = false;
  if (internalChan) {
    DebugOnly<nsresult> rv = internalChan->GetResponseSynthesized(&synthesized);
    MOZ_ASSERT(NS_SUCCEEDED(rv), "GetResponseSynthesized shouldn't fail.");
  }
  return synthesized;
}

nsresult
nsDocument::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
                              nsILoadGroup* aLoadGroup,
                              nsISupports* aContainer,
                              nsIStreamListener **aDocListener,
                              bool aReset, nsIContentSink* aSink)
{
  if (MOZ_LOG_TEST(gDocumentLeakPRLog, LogLevel::Debug)) {
    nsCOMPtr<nsIURI> uri;
    aChannel->GetURI(getter_AddRefs(uri));
    MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
            ("DOCUMENT %p StartDocumentLoad %s",
             this, uri ? uri->GetSpecOrDefault().get() : ""));
  }

  MOZ_ASSERT(NodePrincipal()->GetAppId() != nsIScriptSecurityManager::UNKNOWN_APP_ID,
             "Document should never have UNKNOWN_APP_ID");

  MOZ_ASSERT(GetReadyStateEnum() == nsIDocument::READYSTATE_UNINITIALIZED,
             "Bad readyState");
  SetReadyStateInternal(READYSTATE_LOADING);

  if (nsCRT::strcmp(kLoadAsData, aCommand) == 0) {
    mLoadedAsData = true;
    // We need to disable script & style loading in this case.
    // We leave them disabled even in EndLoad(), and let anyone
    // who puts the document on display to worry about enabling.

    // Do not load/process scripts when loading as data
    ScriptLoader()->SetEnabled(false);

    // styles
    CSSLoader()->SetEnabled(false); // Do not load/process styles when loading as data
  } else if (nsCRT::strcmp("external-resource", aCommand) == 0) {
    // Allow CSS, but not scripts
    ScriptLoader()->SetEnabled(false);
  }

  mMayStartLayout = false;

  if (aReset) {
    Reset(aChannel, aLoadGroup);
  }

  nsAutoCString contentType;
  nsCOMPtr<nsIPropertyBag2> bag = do_QueryInterface(aChannel);
  if ((bag && NS_SUCCEEDED(bag->GetPropertyAsACString(
                NS_LITERAL_STRING("contentType"), contentType))) ||
      NS_SUCCEEDED(aChannel->GetContentType(contentType))) {
    // XXX this is only necessary for viewsource:
    nsACString::const_iterator start, end, semicolon;
    contentType.BeginReading(start);
    contentType.EndReading(end);
    semicolon = start;
    FindCharInReadable(';', semicolon, end);
    SetContentTypeInternal(Substring(start, semicolon));
  }

  RetrieveRelevantHeaders(aChannel);

  mChannel = aChannel;
  nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(mChannel);
  if (inStrmChan) {
    bool isSrcdocChannel;
    inStrmChan->GetIsSrcdocChannel(&isSrcdocChannel);
    if (isSrcdocChannel) {
      mIsSrcdocDocument = true;
    }
  }

  if (mChannel) {
    nsLoadFlags loadFlags;
    mChannel->GetLoadFlags(&loadFlags);
    bool isDocument = false;
    mChannel->GetIsDocument(&isDocument);
    if (loadFlags & nsIRequest::LOAD_DOCUMENT_NEEDS_COOKIE &&
        isDocument &&
        IsSynthesized() &&
        XRE_IsContentProcess()) {
      ContentChild::UpdateCookieStatus(mChannel);
    }
  }

  // If this document is being loaded by a docshell, copy its sandbox flags
  // to the document, and store the fullscreen enabled flag. These are
  // immutable after being set here.
  nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(aContainer);

  // If this is an error page, don't inherit sandbox flags from docshell
  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
  if (docShell && !(loadInfo && loadInfo->GetLoadErrorPage())) {
    nsresult rv = docShell->GetSandboxFlags(&mSandboxFlags);
    NS_ENSURE_SUCCESS(rv, rv);
    WarnIfSandboxIneffective(docShell, mSandboxFlags, GetChannel());
  }

  // The CSP directive upgrade-insecure-requests not only applies to the
  // toplevel document, but also to nested documents. Let's propagate that
  // flag from the parent to the nested document.
  nsCOMPtr<nsIDocShellTreeItem> treeItem = this->GetDocShell();
  if (treeItem) {
    nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
    treeItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
    if (sameTypeParent) {
      nsIDocument* doc = sameTypeParent->GetDocument();
      mBlockAllMixedContent = doc->GetBlockAllMixedContent(false);
      // if the parent document makes use of block-all-mixed-content
      // then subdocument preloads should always be blocked.
      mBlockAllMixedContentPreloads =
        mBlockAllMixedContent || doc->GetBlockAllMixedContent(true);

      mUpgradeInsecureRequests = doc->GetUpgradeInsecureRequests(false);
      // if the parent document makes use of upgrade-insecure-requests
      // then subdocument preloads should always be upgraded.
      mUpgradeInsecurePreloads =
        mUpgradeInsecureRequests || doc->GetUpgradeInsecureRequests(true);
    }
  }

  // If this is not a data document, set CSP.
  if (!mLoadedAsData) {
    nsresult rv = InitCSP(aChannel);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // XFO needs to be checked after CSP because it is ignored if
  // the CSP defines frame-ancestors.
  if (!FramingChecker::CheckFrameOptions(aChannel, docShell, NodePrincipal())) {
    MOZ_LOG(gCspPRLog, LogLevel::Debug,
            ("XFO doesn't like frame's ancestry, not loading."));
    // stop!  ERROR page!
    aChannel->Cancel(NS_ERROR_CSP_FRAME_ANCESTOR_VIOLATION);
  }

  // Perform a async flash classification based on the doc principal
  // in an early stage to reduce the blocking time.
  mFlashClassification = FlashClassification::Unclassified;
  mPrincipalFlashClassifier->AsyncClassify(GetPrincipal());

  return NS_OK;
}

void
nsDocument::SendToConsole(nsCOMArray<nsISecurityConsoleMessage>& aMessages)
{
  for (uint32_t i = 0; i < aMessages.Length(); ++i) {
    nsAutoString messageTag;
    aMessages[i]->GetTag(messageTag);

    nsAutoString category;
    aMessages[i]->GetCategory(category);

    nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                    NS_ConvertUTF16toUTF8(category),
                                    this, nsContentUtils::eSECURITY_PROPERTIES,
                                    NS_ConvertUTF16toUTF8(messageTag).get());
  }
}

void
nsDocument::ApplySettingsFromCSP(bool aSpeculative)
{
  nsresult rv = NS_OK;
  if (!aSpeculative) {
    // 1) apply settings from regular CSP
    nsCOMPtr<nsIContentSecurityPolicy> csp;
    rv = NodePrincipal()->GetCsp(getter_AddRefs(csp));
    NS_ENSURE_SUCCESS_VOID(rv);
    if (csp) {
      // Set up any Referrer Policy specified by CSP
      bool hasReferrerPolicy = false;
      uint32_t referrerPolicy = mozilla::net::RP_Unset;
      rv = csp->GetReferrerPolicy(&referrerPolicy, &hasReferrerPolicy);
      NS_ENSURE_SUCCESS_VOID(rv);
      if (hasReferrerPolicy) {
        mReferrerPolicy = static_cast<ReferrerPolicy>(referrerPolicy);
        mReferrerPolicySet = true;
      }

      // Set up 'block-all-mixed-content' if not already inherited
      // from the parent context or set by any other CSP.
      if (!mBlockAllMixedContent) {
        rv = csp->GetBlockAllMixedContent(&mBlockAllMixedContent);
        NS_ENSURE_SUCCESS_VOID(rv);
      }
      if (!mBlockAllMixedContentPreloads) {
        mBlockAllMixedContentPreloads = mBlockAllMixedContent;
     }

      // Set up 'upgrade-insecure-requests' if not already inherited
      // from the parent context or set by any other CSP.
      if (!mUpgradeInsecureRequests) {
        rv = csp->GetUpgradeInsecureRequests(&mUpgradeInsecureRequests);
        NS_ENSURE_SUCCESS_VOID(rv);
      }
      if (!mUpgradeInsecurePreloads) {
        mUpgradeInsecurePreloads = mUpgradeInsecureRequests;
      }
    }
    return;
  }

  // 2) apply settings from speculative csp
  nsCOMPtr<nsIContentSecurityPolicy> preloadCsp;
  rv = NodePrincipal()->GetPreloadCsp(getter_AddRefs(preloadCsp));
  NS_ENSURE_SUCCESS_VOID(rv);
  if (preloadCsp) {
    if (!mBlockAllMixedContentPreloads) {
      rv = preloadCsp->GetBlockAllMixedContent(&mBlockAllMixedContentPreloads);
      NS_ENSURE_SUCCESS_VOID(rv);
    }
    if (!mUpgradeInsecurePreloads) {
      rv = preloadCsp->GetUpgradeInsecureRequests(&mUpgradeInsecurePreloads);
      NS_ENSURE_SUCCESS_VOID(rv);
    }
  }
}

nsresult
nsDocument::InitCSP(nsIChannel* aChannel)
{
  MOZ_ASSERT(!mScriptGlobalObject,
             "CSP must be initialized before mScriptGlobalObject is set!");
  if (!CSPService::sCSPEnabled) {
    MOZ_LOG(gCspPRLog, LogLevel::Debug,
           ("CSP is disabled, skipping CSP init for document %p", this));
    return NS_OK;
  }

  nsAutoCString tCspHeaderValue, tCspROHeaderValue;

  nsCOMPtr<nsIHttpChannel> httpChannel;
  nsresult rv = GetHttpChannelHelper(aChannel, getter_AddRefs(httpChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (httpChannel) {
    Unused << httpChannel->GetResponseHeader(
        NS_LITERAL_CSTRING("content-security-policy"),
        tCspHeaderValue);

    Unused << httpChannel->GetResponseHeader(
        NS_LITERAL_CSTRING("content-security-policy-report-only"),
        tCspROHeaderValue);
  }
  NS_ConvertASCIItoUTF16 cspHeaderValue(tCspHeaderValue);
  NS_ConvertASCIItoUTF16 cspROHeaderValue(tCspROHeaderValue);

  // Check if this is a document from a WebExtension.
  nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
  auto addonPolicy = BasePrincipal::Cast(principal)->AddonPolicy();

  // Check if this is a signed content to apply default CSP.
  bool applySignedContentCSP = false;
  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
  if (loadInfo && loadInfo->GetVerifySignedContent()) {
    applySignedContentCSP = true;
  }

  // If there's no CSP to apply, go ahead and return early
  if (!addonPolicy &&
      !applySignedContentCSP &&
      cspHeaderValue.IsEmpty() &&
      cspROHeaderValue.IsEmpty()) {
    if (MOZ_LOG_TEST(gCspPRLog, LogLevel::Debug)) {
      nsCOMPtr<nsIURI> chanURI;
      aChannel->GetURI(getter_AddRefs(chanURI));
      nsAutoCString aspec;
      chanURI->GetAsciiSpec(aspec);
      MOZ_LOG(gCspPRLog, LogLevel::Debug,
             ("no CSP for document, %s",
              aspec.get()));
    }

    return NS_OK;
  }

  MOZ_LOG(gCspPRLog, LogLevel::Debug, ("Document is an add-on or CSP header specified %p", this));

  nsCOMPtr<nsIContentSecurityPolicy> csp;
  rv = principal->EnsureCSP(this, getter_AddRefs(csp));
  NS_ENSURE_SUCCESS(rv, rv);

  // ----- if the doc is an addon, apply its CSP.
  if (addonPolicy) {
    nsCOMPtr<nsIAddonPolicyService> aps = do_GetService("@mozilla.org/addons/policy-service;1");

    nsAutoString addonCSP;
    Unused << ExtensionPolicyService::GetSingleton().GetBaseCSP(addonCSP);
    csp->AppendPolicy(addonCSP, false, false);

    csp->AppendPolicy(addonPolicy->ContentSecurityPolicy(), false, false);
  }

  // ----- if the doc is a signed content, apply the default CSP.
  // Note that when the content signing becomes a standard, we might have
  // to restrict this enforcement to "remote content" only.
  if (applySignedContentCSP) {
    nsAutoString signedContentCSP;
    Preferences::GetString("security.signed_content.CSP.default",
                           signedContentCSP);
    csp->AppendPolicy(signedContentCSP, false, false);
  }

  // ----- if there's a full-strength CSP header, apply it.
  if (!cspHeaderValue.IsEmpty()) {
    rv = CSP_AppendCSPFromHeader(csp, cspHeaderValue, false);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // ----- if there's a report-only CSP header, apply it.
  if (!cspROHeaderValue.IsEmpty()) {
    rv = CSP_AppendCSPFromHeader(csp, cspROHeaderValue, true);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // ----- Enforce sandbox policy if supplied in CSP header
  // The document may already have some sandbox flags set (e.g. if the document
  // is an iframe with the sandbox attribute set). If we have a CSP sandbox
  // directive, intersect the CSP sandbox flags with the existing flags. This
  // corresponds to the _least_ permissive policy.
  uint32_t cspSandboxFlags = SANDBOXED_NONE;
  rv = csp->GetCSPSandboxFlags(&cspSandboxFlags);
  NS_ENSURE_SUCCESS(rv, rv);

  // Probably the iframe sandbox attribute already caused the creation of a
  // new NullPrincipal. Only create a new NullPrincipal if CSP requires so
  // and no one has been created yet.
  bool needNewNullPrincipal =
    (cspSandboxFlags & SANDBOXED_ORIGIN) && !(mSandboxFlags & SANDBOXED_ORIGIN);

  mSandboxFlags |= cspSandboxFlags;
  
  if (needNewNullPrincipal) {
    principal = NullPrincipal::CreateWithInheritedAttributes(principal);
    principal->SetCsp(csp);
    SetPrincipal(principal);
  }

  // ----- Enforce frame-ancestor policy on any applied policies
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
  if (docShell) {
    bool safeAncestry = false;

    // PermitsAncestry sends violation reports when necessary
    rv = csp->PermitsAncestry(docShell, &safeAncestry);

    if (NS_FAILED(rv) || !safeAncestry) {
      MOZ_LOG(gCspPRLog, LogLevel::Debug,
              ("CSP doesn't like frame's ancestry, not loading."));
      // stop!  ERROR page!
      aChannel->Cancel(NS_ERROR_CSP_FRAME_ANCESTOR_VIOLATION);
    }
  }
  ApplySettingsFromCSP(false);
  return NS_OK;
}

already_AddRefed<nsIParser>
nsDocument::CreatorParserOrNull()
{
  nsCOMPtr<nsIParser> parser = mParser;
  return parser.forget();
}

void
nsDocument::StopDocumentLoad()
{
  if (mParser) {
    mParserAborted = true;
    mParser->Terminate();
  }
}

void
nsDocument::SetDocumentURI(nsIURI* aURI)
{
  nsCOMPtr<nsIURI> oldBase = GetDocBaseURI();
  mDocumentURI = NS_TryToMakeImmutable(aURI);
  nsIURI* newBase = GetDocBaseURI();

  bool equalBases = false;
  // Changing just the ref of a URI does not change how relative URIs would
  // resolve wrt to it, so we can treat the bases as equal as long as they're
  // equal ignoring the ref.
  if (oldBase && newBase) {
    oldBase->EqualsExceptRef(newBase, &equalBases);
  }
  else {
    equalBases = !oldBase && !newBase;
  }

  // If this is the first time we're setting the document's URI, set the
  // document's original URI.
  if (!mOriginalURI)
    mOriginalURI = mDocumentURI;

  // If changing the document's URI changed the base URI of the document, we
  // need to refresh the hrefs of all the links on the page.
  if (!equalBases) {
    RefreshLinkHrefs();
  }
}

void
nsDocument::SetChromeXHRDocURI(nsIURI* aURI)
{
  mChromeXHRDocURI = aURI;
}

void
nsDocument::SetChromeXHRDocBaseURI(nsIURI* aURI)
{
  mChromeXHRDocBaseURI = aURI;
}

NS_IMETHODIMP
nsDocument::GetLastModified(nsAString& aLastModified)
{
  nsIDocument::GetLastModified(aLastModified);
  return NS_OK;
}

static void
GetFormattedTimeString(PRTime aTime, nsAString& aFormattedTimeString)
{
  PRExplodedTime prtime;
  PR_ExplodeTime(aTime, PR_LocalTimeParameters, &prtime);
  // "MM/DD/YYYY hh:mm:ss"
  char formatedTime[24];
  if (SprintfLiteral(formatedTime, "%02d/%02d/%04d %02d:%02d:%02d",
                     prtime.tm_month + 1, prtime.tm_mday, int(prtime.tm_year),
                     prtime.tm_hour     ,  prtime.tm_min,  prtime.tm_sec)) {
    CopyASCIItoUTF16(nsDependentCString(formatedTime), aFormattedTimeString);
  } else {
    // If we for whatever reason failed to find the last modified time
    // (or even the current time), fall back to what NS4.x returned.
    aFormattedTimeString.AssignLiteral(u"01/01/1970 00:00:00");
  }
}

void
nsIDocument::GetLastModified(nsAString& aLastModified) const
{
  if (!mLastModified.IsEmpty()) {
    aLastModified.Assign(mLastModified);
  } else {
    GetFormattedTimeString(PR_Now(), aLastModified);
  }
}

void
nsDocument::AddToNameTable(Element *aElement, nsIAtom* aName)
{
  MOZ_ASSERT(nsGenericHTMLElement::ShouldExposeNameAsHTMLDocumentProperty(aElement),
             "Only put elements that need to be exposed as document['name'] in "
             "the named table.");

  nsIdentifierMapEntry* entry = mIdentifierMap.PutEntry(aName);

  // Null for out-of-memory
  if (entry) {
    if (!entry->HasNameElement() &&
        !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
      ++mExpandoAndGeneration.generation;
    }
    entry->AddNameElement(this, aElement);
  }
}

void
nsDocument::RemoveFromNameTable(Element *aElement, nsIAtom* aName)
{
  // Speed up document teardown
  if (mIdentifierMap.Count() == 0)
    return;

  nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aName);
  if (!entry) // Could be false if the element was anonymous, hence never added
    return;

  entry->RemoveNameElement(aElement);
  if (!entry->HasNameElement() &&
      !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
    ++mExpandoAndGeneration.generation;
  }
}

void
nsDocument::AddToIdTable(Element *aElement, nsIAtom* aId)
{
  nsIdentifierMapEntry* entry = mIdentifierMap.PutEntry(aId);

  if (entry) { /* True except on OOM */
    if (nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(aElement) &&
        !entry->HasNameElement() &&
        !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
      ++mExpandoAndGeneration.generation;
    }
    entry->AddIdElement(aElement);
  }
}

void
nsDocument::RemoveFromIdTable(Element *aElement, nsIAtom* aId)
{
  NS_ASSERTION(aId, "huhwhatnow?");

  // Speed up document teardown
  if (mIdentifierMap.Count() == 0) {
    return;
  }

  nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aId);
  if (!entry) // Can be null for XML elements with changing ids.
    return;

  entry->RemoveIdElement(aElement);
  if (nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(aElement) &&
      !entry->HasNameElement() &&
      !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
    ++mExpandoAndGeneration.generation;
  }
  if (entry->IsEmpty()) {
    mIdentifierMap.RemoveEntry(entry);
  }
}

nsIPrincipal*
nsDocument::GetPrincipal()
{
  return NodePrincipal();
}

extern bool sDisablePrefetchHTTPSPref;

void
nsDocument::SetPrincipal(nsIPrincipal *aNewPrincipal)
{
  if (aNewPrincipal && mAllowDNSPrefetch && sDisablePrefetchHTTPSPref) {
    nsCOMPtr<nsIURI> uri;
    aNewPrincipal->GetURI(getter_AddRefs(uri));
    bool isHTTPS;
    if (!uri || NS_FAILED(uri->SchemeIs("https", &isHTTPS)) ||
        isHTTPS) {
      mAllowDNSPrefetch = false;
    }
  }
  mNodeInfoManager->SetDocumentPrincipal(aNewPrincipal);

#ifdef DEBUG
  // Validate that the docgroup is set correctly by calling its getter and
  // triggering its sanity check.
  //
  // If we're setting the principal to null, we don't want to perform the check,
  // as the document is entering an intermediate state where it does not have a
  // principal. It will be given another real principal shortly which we will
  // check. It's not unsafe to have a document which has a null principal in the
  // same docgroup as another document, so this should not be a problem.
  if (aNewPrincipal) {
    GetDocGroup();
  }
#endif
}

mozilla::dom::DocGroup*
nsIDocument::GetDocGroup() const
{
#ifdef DEBUG
  // Sanity check that we have an up-to-date and accurate docgroup
  if (mDocGroup) {
    nsAutoCString docGroupKey;

    // GetKey() can fail, e.g. after the TLD service has shut down.
    nsresult rv = mozilla::dom::DocGroup::GetKey(NodePrincipal(), docGroupKey);
    if (NS_SUCCEEDED(rv)) {
      MOZ_ASSERT(mDocGroup->MatchesKey(docGroupKey));
    }
    // XXX: Check that the TabGroup is correct as well!
  }
#endif

  return mDocGroup;
}

nsresult
nsIDocument::Dispatch(TaskCategory aCategory,
                      already_AddRefed<nsIRunnable>&& aRunnable)
{
  // Note that this method may be called off the main thread.
  if (mDocGroup) {
    return mDocGroup->Dispatch(aCategory, Move(aRunnable));
  }
  return DispatcherTrait::Dispatch(aCategory, Move(aRunnable));
}

nsISerialEventTarget*
nsIDocument::EventTargetFor(TaskCategory aCategory) const
{
  if (mDocGroup) {
    return mDocGroup->EventTargetFor(aCategory);
  }
  return DispatcherTrait::EventTargetFor(aCategory);
}

AbstractThread*
nsIDocument::AbstractMainThreadFor(mozilla::TaskCategory aCategory)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (mDocGroup) {
    return mDocGroup->AbstractMainThreadFor(aCategory);
  }
  return DispatcherTrait::AbstractMainThreadFor(aCategory);
}

void
nsIDocument::NoteScriptTrackingStatus(const nsACString& aURL, bool aIsTracking)
{
  if (aIsTracking) {
    mTrackingScripts.PutEntry(aURL);
  } else {
    MOZ_ASSERT(!mTrackingScripts.Contains(aURL));
  }
}

bool
nsIDocument::IsScriptTracking(const nsACString& aURL) const
{
  return mTrackingScripts.Contains(aURL);
}

bool
nsIDocument::PrerenderHref(nsIURI* aHref)
{
  MOZ_ASSERT(aHref);

  static bool sPrerenderEnabled = false;
  static bool sPrerenderPrefCached = false;
  if (!sPrerenderPrefCached) {
    sPrerenderPrefCached = true;
    Preferences::AddBoolVarCache(&sPrerenderEnabled,
                                 "dom.linkPrerender.enabled",
                                 false);
  }

  // Check if prerender is enabled
  if (!sPrerenderEnabled) {
    return false;
  }

  nsCOMPtr<nsIURI> referrer = GetDocumentURI();
  bool urisMatch = false;
  aHref->EqualsExceptRef(referrer, &urisMatch);
  if (urisMatch) {
    // Prerender current document isn't quite meaningful, and we may not be able
    // to load it out of process.
    return false;
  }

  nsCOMPtr<nsIDocShell> docShell = GetDocShell();
  nsCOMPtr<nsIWebNavigation> webNav = do_QueryInterface(docShell);
  NS_ENSURE_TRUE(webNav, false);

  bool canGoForward = false;
  nsresult rv = webNav->GetCanGoForward(&canGoForward);
  if (NS_FAILED(rv) || canGoForward) {
    // Skip prerender on history navigation as we don't support it yet.
    // Remove this check once bug 1323650 is implemented.
    return false;
  }

  // Check if the document is in prerender state. We don't prerender in a
  // prerendered document.
  if (docShell->GetIsPrerendered()) {
    return false;
  }

  // We currently do not support prerendering in documents loaded within the
  // chrome process.
  if (!XRE_IsContentProcess()) {
    return false;
  }

  // Adopting an prerendered document is similar to performing a load within a
  // different docshell, as the prerendering must have occurred in a different
  // docshell.
  if (!docShell->GetIsOnlyToplevelInTabGroup()) {
    return false;
  }

  TabChild* tabChild = TabChild::GetFrom(docShell);
  NS_ENSURE_TRUE(tabChild, false);

  nsCOMPtr<nsIWebBrowserChrome3> wbc3;
  tabChild->GetWebBrowserChrome(getter_AddRefs(wbc3));
  NS_ENSURE_TRUE(wbc3, false);

  rv = wbc3->StartPrerenderingDocument(aHref, referrer, NodePrincipal());
  NS_ENSURE_SUCCESS(rv, false);

  return true;
}

NS_IMETHODIMP
nsDocument::GetApplicationCache(nsIApplicationCache **aApplicationCache)
{
  NS_IF_ADDREF(*aApplicationCache = mApplicationCache);

  return NS_OK;
}

NS_IMETHODIMP
nsDocument::SetApplicationCache(nsIApplicationCache *aApplicationCache)
{
  mApplicationCache = aApplicationCache;

  return NS_OK;
}

NS_IMETHODIMP
nsDocument::GetContentType(nsAString& aContentType)
{
  CopyUTF8toUTF16(GetContentTypeInternal(), aContentType);

  return NS_OK;
}

void
nsDocument::SetContentType(const nsAString& aContentType)
{
  SetContentTypeInternal(NS_ConvertUTF16toUTF8(aContentType));
}

bool
nsDocument::GetAllowPlugins()
{
  // First, we ask our docshell if it allows plugins.
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);

  if (docShell) {
    bool allowPlugins = false;
    docShell->GetAllowPlugins(&allowPlugins);
    if (!allowPlugins) {
      return false;
    }

    // If the docshell allows plugins, we check whether
    // we are sandboxed and plugins should not be allowed.
    if (mSandboxFlags & SANDBOXED_PLUGINS) {
      return false;
    }
  }

  FlashClassification classification = DocumentFlashClassification();
  if (classification == FlashClassification::Denied) {
    return false;
  }

  return true;
}

bool
nsDocument::IsElementAnimateEnabled(JSContext* aCx, JSObject* /*unused*/)
{
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         nsContentUtils::AnimationsAPICoreEnabled() ||
         nsContentUtils::AnimationsAPIElementAnimateEnabled();
}

bool
nsDocument::IsWebAnimationsEnabled(JSContext* aCx, JSObject* /*unused*/)
{
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         nsContentUtils::AnimationsAPICoreEnabled();
}

DocumentTimeline*
nsDocument::Timeline()
{
  if (!mDocumentTimeline) {
    mDocumentTimeline = new DocumentTimeline(this, TimeDuration(0));
  }

  return mDocumentTimeline;
}

void
nsDocument::GetAnimations(nsTArray<RefPtr<Animation>>& aAnimations)
{
  // Hold a strong ref for the root element since Element::GetAnimations() calls
  // FlushPendingNotifications() which may destroy the element.
  RefPtr<Element> root = GetRootElement();
  if (!root) {
    return;
  }
  AnimationFilter filter;
  filter.mSubtree = true;
  root->GetAnimations(filter, aAnimations);
}

SVGSVGElement*
nsIDocument::GetSVGRootElement() const
{
  Element* root = GetRootElement();
  if (!root || !root->IsSVGElement(nsGkAtoms::svg)) {
    return nullptr;
  }
  return static_cast<SVGSVGElement*>(root);
}

/* Return true if the document is in the focused top-level window, and is an
 * ancestor of the focused DOMWindow. */
NS_IMETHODIMP
nsDocument::HasFocus(bool* aResult)
{
  ErrorResult rv;
  *aResult = nsIDocument::HasFocus(rv);
  return rv.StealNSResult();
}

bool
nsIDocument::HasFocus(ErrorResult& rv) const
{
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm) {
    rv.Throw(NS_ERROR_NOT_AVAILABLE);
    return false;
  }

  // Is there a focused DOMWindow?
  nsCOMPtr<mozIDOMWindowProxy> focusedWindow;
  fm->GetFocusedWindow(getter_AddRefs(focusedWindow));
  if (!focusedWindow) {
    return false;
  }

  nsPIDOMWindowOuter* piWindow = nsPIDOMWindowOuter::From(focusedWindow);

  // Are we an ancestor of the focused DOMWindow?
  for (nsIDocument* currentDoc = piWindow->GetDoc(); currentDoc;
       currentDoc = currentDoc->GetParentDocument()) {
    if (currentDoc == this) {
      // Yes, we are an ancestor
      return true;
    }
  }

  return false;
}

TimeStamp
nsIDocument::LastFocusTime() const
{
  return mLastFocusTime;
}

void
nsIDocument::SetLastFocusTime(const TimeStamp& aFocusTime)
{
  MOZ_DIAGNOSTIC_ASSERT(!aFocusTime.IsNull());
  MOZ_DIAGNOSTIC_ASSERT(mLastFocusTime.IsNull() ||
                        aFocusTime >= mLastFocusTime);
  mLastFocusTime = aFocusTime;
}

NS_IMETHODIMP
nsDocument::GetReferrer(nsAString& aReferrer)
{
  nsIDocument::GetReferrer(aReferrer);
  return NS_OK;
}

void
nsIDocument::GetReferrer(nsAString& aReferrer) const
{
  if (mIsSrcdocDocument && mParentDocument)
      mParentDocument->GetReferrer(aReferrer);
  else
    CopyUTF8toUTF16(mReferrer, aReferrer);
}

nsresult
nsIDocument::GetSrcdocData(nsAString &aSrcdocData)
{
  if (mIsSrcdocDocument) {
    nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(mChannel);
    if (inStrmChan) {
      return inStrmChan->GetSrcdocData(aSrcdocData);
    }
  }
  aSrcdocData = NullString();
  return NS_OK;
}

NS_IMETHODIMP
nsDocument::GetActiveElement(nsIDOMElement **aElement)
{
  nsCOMPtr<nsIDOMElement> el(do_QueryInterface(nsIDocument::GetActiveElement()));
  el.forget(aElement);
  return NS_OK;
}

Element*
nsIDocument::GetActiveElement()
{
  // Get the focused element.
  if (nsCOMPtr<nsPIDOMWindowOuter> window = GetWindow()) {
    nsCOMPtr<nsPIDOMWindowOuter> focusedWindow;
    nsIContent* focusedContent =
      nsFocusManager::GetFocusedDescendant(window,
                                           nsFocusManager::eOnlyCurrentWindow,
                                           getter_AddRefs(focusedWindow));
    // be safe and make sure the element is from this document
    if (focusedContent && focusedContent->OwnerDoc() == this) {
      if (focusedContent->ChromeOnlyAccess()) {
        focusedContent = focusedContent->FindFirstNonChromeOnlyAccessContent();
      }
      if (focusedContent) {
        return focusedContent->AsElement();
      }
    }
  }

  // No focused element anywhere in this document.  Try to get the BODY.
  RefPtr<nsHTMLDocument> htmlDoc = AsHTMLDocument();
  if (htmlDoc) {
    // Because of IE compatibility, return null when html document doesn't have
    // a body.
    return htmlDoc->GetBody();
  }

  // If we couldn't get a BODY, return the root element.
  return GetDocumentElement();
}

NS_IMETHODIMP
nsDocument::GetCurrentScript(nsIDOMElement **aElement)
{
  nsCOMPtr<nsIDOMElement> el(do_QueryInterface(nsIDocument::GetCurrentScript()));
  el.forget(aElement);
  return NS_OK;
}

Element*
nsIDocument::GetCurrentScript()
{
  nsCOMPtr<Element> el(do_QueryInterface(ScriptLoader()->GetCurrentScript()));
  return el;
}

NS_IMETHODIMP
nsDocument::ElementFromPoint(float aX, float aY, nsIDOMElement** aReturn)
{
  Element* el = nsIDocument::ElementFromPoint(aX, aY);
  nsCOMPtr<nsIDOMElement> retval = do_QueryInterface(el);
  retval.forget(aReturn);
  return NS_OK;
}

Element*
nsIDocument::ElementFromPoint(float aX, float aY)
{
  return ElementFromPointHelper(aX, aY, false, true);
}

void
nsIDocument::ElementsFromPoint(float aX, float aY,
                               nsTArray<RefPtr<Element>>& aElements)
{
  ElementsFromPointHelper(aX, aY, nsIDocument::FLUSH_LAYOUT, aElements);
}

Element*
nsDocument::ElementFromPointHelper(float aX, float aY,
                                   bool aIgnoreRootScrollFrame,
                                   bool aFlushLayout)
{
  AutoTArray<RefPtr<Element>, 1> elementArray;
  ElementsFromPointHelper(aX, aY,
                          ((aIgnoreRootScrollFrame ? nsIDocument::IGNORE_ROOT_SCROLL_FRAME : 0) |
                           (aFlushLayout ? nsIDocument::FLUSH_LAYOUT : 0) |
                           nsIDocument::IS_ELEMENT_FROM_POINT),
                          elementArray);
  if (elementArray.IsEmpty()) {
    return nullptr;
  }
  return elementArray[0];
}

void
nsDocument::ElementsFromPointHelper(float aX, float aY,
                                    uint32_t aFlags,
                                    nsTArray<RefPtr<mozilla::dom::Element>>& aElements)
{
  // As per the the spec, we return null if either coord is negative
  if (!(aFlags & nsIDocument::IGNORE_ROOT_SCROLL_FRAME) && (aX < 0 || aY < 0)) {
    return;
  }

  nscoord x = nsPresContext::CSSPixelsToAppUnits(aX);
  nscoord y = nsPresContext::CSSPixelsToAppUnits(aY);
  nsPoint pt(x, y);

  // Make sure the layout information we get is up-to-date, and
  // ensure we get a root frame (for everything but XUL)
  if (aFlags & nsIDocument::FLUSH_LAYOUT) {
    FlushPendingNotifications(FlushType::Layout);
  }

  nsIPresShell *ps = GetShell();
  if (!ps) {
    return;
  }
  nsIFrame *rootFrame = ps->GetRootFrame();

  // XUL docs, unlike HTML, have no frame tree until everything's done loading
  if (!rootFrame) {
    return; // return null to premature XUL callers as a reminder to wait
  }

  nsTArray<nsIFrame*> outFrames;
  // Emulate what GetFrameAtPoint does, since we want all the frames under our
  // point.
  nsLayoutUtils::GetFramesForArea(rootFrame, nsRect(pt, nsSize(1, 1)), outFrames,
    nsLayoutUtils::IGNORE_PAINT_SUPPRESSION | nsLayoutUtils::IGNORE_CROSS_DOC |
    ((aFlags & nsIDocument::IGNORE_ROOT_SCROLL_FRAME) ? nsLayoutUtils::IGNORE_ROOT_SCROLL_FRAME : 0));

  // Dunno when this would ever happen, as we should at least have a root frame under us?
  if (outFrames.IsEmpty()) {
    return;
  }

  // Used to filter out repeated elements in sequence.
  nsIContent* lastAdded = nullptr;

  for (uint32_t i = 0; i < outFrames.Length(); i++) {
    nsIContent* node = GetContentInThisDocument(outFrames[i]);

    if (!node || !node->IsElement()) {
      // If this helper is called via ElementsFromPoint, we need to make sure
      // our frame is an element. Otherwise return whatever the top frame is
      // even if it isn't the top-painted element.
      if (!(aFlags & nsIDocument::IS_ELEMENT_FROM_POINT)) {
        continue;
      }
      node = node->GetParent();
    }
    if (node && node != lastAdded) {
      aElements.AppendElement(node->AsElement());
      lastAdded = node;
      // If this helper is called via ElementFromPoint, just return the first
      // element we find.
      if (aFlags & nsIDocument::IS_ELEMENT_FROM_POINT) {
        return;
      }
    }
  }
}

nsresult
nsDocument::NodesFromRectHelper(float aX, float aY,
                                float aTopSize, float aRightSize,
                                float aBottomSize, float aLeftSize,
                                bool aIgnoreRootScrollFrame,
                                bool aFlushLayout,
                                nsIDOMNodeList** aReturn)
{
  NS_ENSURE_ARG_POINTER(aReturn);

  nsSimpleContentList* elements = new nsSimpleContentList(this);
  NS_ADDREF(elements);
  *aReturn = elements;

  // Following the same behavior of elementFromPoint,
  // we don't return anything if either coord is negative
  if (!aIgnoreRootScrollFrame && (aX < 0 || aY < 0))
    return NS_OK;

  nscoord x = nsPresContext::CSSPixelsToAppUnits(aX - aLeftSize);
  nscoord y = nsPresContext::CSSPixelsToAppUnits(aY - aTopSize);
  nscoord w = nsPresContext::CSSPixelsToAppUnits(aLeftSize + aRightSize) + 1;
  nscoord h = nsPresContext::CSSPixelsToAppUnits(aTopSize + aBottomSize) + 1;

  nsRect rect(x, y, w, h);

  // Make sure the layout information we get is up-to-date, and
  // ensure we get a root frame (for everything but XUL)
  if (aFlushLayout) {
    FlushPendingNotifications(FlushType::Layout);
  }

  nsIPresShell *ps = GetShell();
  NS_ENSURE_STATE(ps);
  nsIFrame *rootFrame = ps->GetRootFrame();

  // XUL docs, unlike HTML, have no frame tree until everything's done loading
  if (!rootFrame)
    return NS_OK; // return nothing to premature XUL callers as a reminder to wait

  AutoTArray<nsIFrame*,8> outFrames;
  nsLayoutUtils::GetFramesForArea(rootFrame, rect, outFrames,
    nsLayoutUtils::IGNORE_PAINT_SUPPRESSION | nsLayoutUtils::IGNORE_CROSS_DOC |
    (aIgnoreRootScrollFrame ? nsLayoutUtils::IGNORE_ROOT_SCROLL_FRAME : 0));

  // Used to filter out repeated elements in sequence.
  nsIContent* lastAdded = nullptr;

  for (uint32_t i = 0; i < outFrames.Length(); i++) {
    nsIContent* node = GetContentInThisDocument(outFrames[i]);

    if (node && !node->IsElement() && !node->IsNodeOfType(nsINode::eTEXT)) {
      // We have a node that isn't an element or a text node,
      // use its parent content instead.
      node = node->GetParent();
    }
    if (node && node != lastAdded) {
      elements->AppendElement(node);
      lastAdded = node;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocument::GetElementsByClassName(const nsAString& aClasses,
                                   nsIDOMNodeList** aReturn)
{
  *aReturn = nsIDocument::GetElementsByClassName(aClasses).take();
  return NS_OK;
}

already_AddRefed<nsContentList>
nsIDocument::GetElementsByClassName(const nsAString& aClasses)
{
  return nsContentUtils::GetElementsByClassName(this, aClasses);
}

void
nsIDocument::ReleaseCapture() const
{
  // only release the capture if the caller can access it. This prevents a
  // page from stopping a scrollbar grab for example.
  nsCOMPtr<nsINode> node = nsIPresShell::GetCapturingContent();
  if (node && nsContentUtils::CanCallerAccess(node)) {
    nsIPresShell::SetCapturingContent(nullptr, 0);
  }
}

already_AddRefed<nsIURI>
nsIDocument::GetBaseURI(bool aTryUseXHRDocBaseURI) const
{
  nsCOMPtr<nsIURI> uri;
  if (aTryUseXHRDocBaseURI && mChromeXHRDocBaseURI) {
    uri = mChromeXHRDocBaseURI;
  } else {
    uri = GetDocBaseURI();
  }

  return uri.forget();
}

void
nsDocument::SetBaseURI(nsIURI* aURI)
{
  if (!aURI && !mDocumentBaseURI) {
    return;
  }

  // Don't do anything if the URI wasn't actually changed.
  if (aURI && mDocumentBaseURI) {
    bool equalBases = false;
    mDocumentBaseURI->Equals(aURI, &equalBases);
    if (equalBases) {
      return;
    }
  }

  if (aURI) {
    mDocumentBaseURI = NS_TryToMakeImmutable(aURI);
  } else {
    mDocumentBaseURI = nullptr;
  }
  RefreshLinkHrefs();
}

URLExtraData*
nsIDocument::DefaultStyleAttrURLData()
{
#ifdef MOZ_STYLO
  MOZ_ASSERT(NS_IsMainThread());
  nsIURI* baseURI = GetDocBaseURI();
  nsIURI* docURI = GetDocumentURI();
  nsIPrincipal* principal = NodePrincipal();
  if (!mCachedURLData ||
      mCachedURLData->BaseURI() != baseURI ||
      mCachedURLData->GetReferrer() != docURI ||
      mCachedURLData->GetPrincipal() != principal) {
    mCachedURLData = new URLExtraData(baseURI, docURI, principal);
  }
  return mCachedURLData;
#else
  MOZ_CRASH("Should not be called for non-stylo build");
  return nullptr;
#endif
}

void
nsDocument::GetBaseTarget(nsAString &aBaseTarget)
{
  aBaseTarget = mBaseTarget;
}

void
nsDocument::SetDocumentCharacterSet(NotNull<const Encoding*> aEncoding)
{
  if (mCharacterSet != aEncoding) {
    mCharacterSet = aEncoding;

    if (nsIPresShell* shell = GetShell()) {
      if (nsPresContext* context = shell->GetPresContext()) {
        context->DispatchCharSetChange(aEncoding);
      }
    }
  }
}

void
nsIDocument::GetSandboxFlagsAsString(nsAString& aFlags)
{
  nsContentUtils::SandboxFlagsToString(mSandboxFlags, aFlags);
}

void
nsDocument::GetHeaderData(nsIAtom* aHeaderField, nsAString& aData) const
{
  aData.Truncate();
  const nsDocHeaderData* data = mHeaderData;
  while (data) {
    if (data->mField == aHeaderField) {
      aData = data->mData;

      break;
    }
    data = data->mNext;
  }
}

void
nsDocument::SetHeaderData(nsIAtom* aHeaderField, const nsAString& aData)
{
  if (!aHeaderField) {
    NS_ERROR("null headerField");
    return;
  }

  if (!mHeaderData) {
    if (!aData.IsEmpty()) { // don't bother storing empty string
      mHeaderData = new nsDocHeaderData(aHeaderField, aData);
    }
  }
  else {
    nsDocHeaderData* data = mHeaderData;
    nsDocHeaderData** lastPtr = &mHeaderData;
    bool found = false;
    do {  // look for existing and replace
      if (data->mField == aHeaderField) {
        if (!aData.IsEmpty()) {
          data->mData.Assign(aData);
        }
        else {  // don't store empty string
          *lastPtr = data->mNext;
          data->mNext = nullptr;
          delete data;
        }
        found = true;

        break;
      }
      lastPtr = &(data->mNext);
      data = *lastPtr;
    } while (data);

    if (!aData.IsEmpty() && !found) {
      // didn't find, append
      *lastPtr = new nsDocHeaderData(aHeaderField, aData);
    }
  }

  if (aHeaderField == nsGkAtoms::headerContentLanguage) {
    CopyUTF16toUTF8(aData, mContentLanguage);
  }

  if (aHeaderField == nsGkAtoms::headerDefaultStyle) {
    // Only mess with our stylesheets if we don't have a lastStyleSheetSet, per
    // spec.
    if (DOMStringIsNull(mLastStyleSheetSet)) {
      // Calling EnableStyleSheetsForSetInternal, not SetSelectedStyleSheetSet,
      // per spec.  The idea here is that we're changing our preferred set and
      // that shouldn't change the value of lastStyleSheetSet.  Also, we're
      // using the Internal version so we can update the CSSLoader and not have
      // to worry about null strings.
      EnableStyleSheetsForSetInternal(aData, true);
    }
  }

  if (aHeaderField == nsGkAtoms::refresh) {
    // We get into this code before we have a script global yet, so get to
    // our container via mDocumentContainer.
    nsCOMPtr<nsIRefreshURI> refresher(mDocumentContainer);
    if (refresher) {
      // Note: using mDocumentURI instead of mBaseURI here, for consistency
      // (used to just use the current URI of our webnavigation, but that
      // should really be the same thing).  Note that this code can run
      // before the current URI of the webnavigation has been updated, so we
      // can't assert equality here.
      refresher->SetupRefreshURIFromHeader(mDocumentURI, NodePrincipal(),
                                           NS_ConvertUTF16toUTF8(aData));
    }
  }

  if (aHeaderField == nsGkAtoms::headerDNSPrefetchControl &&
      mAllowDNSPrefetch) {
    // Chromium treats any value other than 'on' (case insensitive) as 'off'.
    mAllowDNSPrefetch = aData.IsEmpty() || aData.LowerCaseEqualsLiteral("on");
  }

  if (aHeaderField == nsGkAtoms::viewport ||
      aHeaderField == nsGkAtoms::handheldFriendly ||
      aHeaderField == nsGkAtoms::viewport_minimum_scale ||
      aHeaderField == nsGkAtoms::viewport_maximum_scale ||
      aHeaderField == nsGkAtoms::viewport_initial_scale ||
      aHeaderField == nsGkAtoms::viewport_height ||
      aHeaderField == nsGkAtoms::viewport_width ||
      aHeaderField ==  nsGkAtoms::viewport_user_scalable) {
    mViewportType = Unknown;
  }

  // Referrer policy spec says to ignore any empty referrer policies.
  if (aHeaderField == nsGkAtoms::referrer && !aData.IsEmpty()) {
     ReferrerPolicy policy = mozilla::net::ReferrerPolicyFromString(aData);
    // If policy is not the empty string, then set element's node document's
    // referrer policy to policy
    if (policy != mozilla::net::RP_Unset) {
      // Referrer policy spec (section 6.1) says that we always use the newest
      // referrer policy we find
      mReferrerPolicy = policy;
      mReferrerPolicySet = true;
    }
  }

  if (aHeaderField == nsGkAtoms::headerReferrerPolicy && !aData.IsEmpty()) {
     ReferrerPolicy policy = nsContentUtils::GetReferrerPolicyFromHeader(aData);
    if (policy != mozilla::net::RP_Unset) {
      mReferrerPolicy = policy;
      mReferrerPolicySet = true;
    }
  }

}
void
nsDocument::TryChannelCharset(nsIChannel *aChannel,
                              int32_t& aCharsetSource,
                              NotNull<const Encoding*>& aEncoding,
                              nsHtml5TreeOpExecutor* aExecutor)
{
  if (aChannel) {
    nsAutoCString charsetVal;
    nsresult rv = aChannel->GetContentCharset(charsetVal);
    if (NS_SUCCEEDED(rv)) {
      const Encoding* preferred = Encoding::ForLabel(charsetVal);
      if (preferred) {
        aEncoding = WrapNotNull(preferred);
        aCharsetSource = kCharsetFromChannel;
        return;
      } else if (aExecutor && !charsetVal.IsEmpty()) {
        aExecutor->ComplainAboutBogusProtocolCharset(this);
      }
    }
  }
}

already_AddRefed<nsIPresShell>
nsDocument::CreateShell(nsPresContext* aContext, nsViewManager* aViewManager,
                        StyleSetHandle aStyleSet)
{
  NS_ASSERTION(!mPresShell, "We have a presshell already!");

  NS_ENSURE_FALSE(GetBFCacheEntry(), nullptr);

  FillStyleSet(aStyleSet);

  // Ensure we start with no stale data in the tree.
  ClearStaleServoDataFromDocument();

  RefPtr<PresShell> shell = new PresShell;
  shell->Init(this, aContext, aViewManager, aStyleSet);

  // Note: we don't hold a ref to the shell (it holds a ref to us)
  mPresShell = shell;

  // Make sure to never paint if we belong to an invisible DocShell.
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
  if (docShell && docShell->IsInvisible())
    shell->SetNeverPainting(true);

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p with PressShell %p and DocShell %p",
                                                this, shell.get(), docShell.get()));

  mExternalResourceMap.ShowViewers();

  UpdateFrameRequestCallbackSchedulingState();

  // Now that we have a shell, we might have @font-face rules.
  RebuildUserFontSet();

  return shell.forget();
}

void
nsIDocument::UpdateFrameRequestCallbackSchedulingState(nsIPresShell* aOldShell)
{
  // If the condition for shouldBeScheduled changes to depend on some other
  // variable, add UpdateFrameRequestCallbackSchedulingState() calls to the
  // places where that variable can change.
  bool shouldBeScheduled =
    mPresShell && IsEventHandlingEnabled() && !mFrameRequestCallbacks.IsEmpty();
  if (shouldBeScheduled == mFrameRequestCallbacksScheduled) {
    // nothing to do
    return;
  }

  nsIPresShell* presShell = aOldShell ? aOldShell : mPresShell;
  MOZ_RELEASE_ASSERT(presShell);

  nsRefreshDriver* rd = presShell->GetPresContext()->RefreshDriver();
  if (shouldBeScheduled) {
    rd->ScheduleFrameRequestCallbacks(this);
  } else {
    rd->RevokeFrameRequestCallbacks(this);
  }

  mFrameRequestCallbacksScheduled = shouldBeScheduled;
}

void
nsIDocument::TakeFrameRequestCallbacks(FrameRequestCallbackList& aCallbacks)
{
  aCallbacks.AppendElements(mFrameRequestCallbacks);
  mFrameRequestCallbacks.Clear();
  // No need to manually remove ourselves from the refresh driver; it will
  // handle that part.  But we do have to update our state.
  mFrameRequestCallbacksScheduled = false;
}

bool
nsIDocument::ShouldThrottleFrameRequests()
{
  if (mStaticCloneCount > 0) {
    // Even if we're not visible, a static clone may be, so run at full speed.
    return false;
  }

  if (Hidden()) {
    // We're not visible (probably in a background tab or the bf cache).
    return true;
  }

  if (!mPresShell) {
    return false;  // Can't do anything smarter.
  }

  nsIFrame* frame = mPresShell->GetRootFrame();
  if (!frame) {
    return false;  // Can't do anything smarter.
  }

  nsIFrame* displayRootFrame = nsLayoutUtils::GetDisplayRootFrame(frame);
  if (!displayRootFrame) {
    return false;  // Can't do anything smarter.
  }

  if (!displayRootFrame->DidPaintPresShell(mPresShell)) {
    // We didn't get painted during the last paint, so we're not visible.
    // Throttle. Note that because we have to paint this document at least
    // once to unthrottle it, we will drop one requestAnimationFrame frame
    // when a document that previously wasn't visible scrolls into view. This
    // is acceptable since it would happen outside the viewport on APZ
    // platforms and is unlikely to be human-perceivable on non-APZ platforms.
    return true;
  }

  // We got painted during the last paint, so run at full speed.
  return false;
}

void
nsDocument::DeleteShell()
{
  mExternalResourceMap.HideViewers();
  if (nsPresContext* presContext = mPresShell->GetPresContext()) {
    presContext->RefreshDriver()->CancelPendingEvents(this);
  }

  // When our shell goes away, request that all our images be immediately
  // discarded, so we don't carry around decoded image data for a document we
  // no longer intend to paint.
  ImageTracker()->RequestDiscardAll();

  // Now that we no longer have a shell, we need to forget about any FontFace
  // objects for @font-face rules that came from the style set.
  RebuildUserFontSet();

  nsIPresShell* oldShell = mPresShell;
  mPresShell = nullptr;
  UpdateFrameRequestCallbackSchedulingState(oldShell);
  mStyleSetFilled = false;

  // Record that the tree might have stale Servo element data in it
  // that would need to be cleared if we ever get a new pres shell
  // or if we call ServoStyleSet style resolving functions on
  // elements in the document. Most of the time this lazy clearing
  // of Servo element data saves us work, since it's not often that a
  // document gets a new pres shell after its old one is destroyed.
  // In those cases we rely on the data being cleared in UnbindFromTree
  // and save this additional traversal.
  if (IsStyledByServo()) {
    mMightHaveStaleServoData = true;
  }
}

static void
SubDocClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry)
{
  SubDocMapEntry *e = static_cast<SubDocMapEntry *>(entry);

  NS_RELEASE(e->mKey);
  if (e->mSubDocument) {
    e->mSubDocument->SetParentDocument(nullptr);
    NS_RELEASE(e->mSubDocument);
  }
}

static void
SubDocInitEntry(PLDHashEntryHdr *entry, const void *key)
{
  SubDocMapEntry *e =
    const_cast<SubDocMapEntry *>
              (static_cast<const SubDocMapEntry *>(entry));

  e->mKey = const_cast<Element*>(static_cast<const Element*>(key));
  NS_ADDREF(e->mKey);

  e->mSubDocument = nullptr;
}

nsresult
nsDocument::SetSubDocumentFor(Element* aElement, nsIDocument* aSubDoc)
{
  NS_ENSURE_TRUE(aElement, NS_ERROR_UNEXPECTED);

  if (!aSubDoc) {
    // aSubDoc is nullptr, remove the mapping

    if (mSubDocuments) {
      mSubDocuments->Remove(aElement);
    }
  } else {
    if (!mSubDocuments) {
      // Create a new hashtable

      static const PLDHashTableOps hash_table_ops =
      {
        PLDHashTable::HashVoidPtrKeyStub,
        PLDHashTable::MatchEntryStub,
        PLDHashTable::MoveEntryStub,
        SubDocClearEntry,
        SubDocInitEntry
      };

      mSubDocuments = new PLDHashTable(&hash_table_ops, sizeof(SubDocMapEntry));
    }

    // Add a mapping to the hash table
    auto entry =
      static_cast<SubDocMapEntry*>(mSubDocuments->Add(aElement, fallible));

    if (!entry) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    if (entry->mSubDocument) {
      entry->mSubDocument->SetParentDocument(nullptr);

      // Release the old sub document
      NS_RELEASE(entry->mSubDocument);
    }

    entry->mSubDocument = aSubDoc;
    NS_ADDREF(entry->mSubDocument);

    aSubDoc->SetParentDocument(this);
  }

  return NS_OK;
}

nsIDocument*
nsDocument::GetSubDocumentFor(nsIContent *aContent) const
{
  if (mSubDocuments && aContent->IsElement()) {
    auto entry = static_cast<SubDocMapEntry*>
                            (mSubDocuments->Search(aContent->AsElement()));

    if (entry) {
      return entry->mSubDocument;
    }
  }

  return nullptr;
}

Element*
nsDocument::FindContentForSubDocument(nsIDocument *aDocument) const
{
  NS_ENSURE_TRUE(aDocument, nullptr);

  if (!mSubDocuments) {
    return nullptr;
  }

  for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
    auto entry = static_cast<SubDocMapEntry*>(iter.Get());
    if (entry->mSubDocument == aDocument) {
      return entry->mKey;
    }
  }
  return nullptr;
}

bool
nsDocument::IsNodeOfType(uint32_t aFlags) const
{
    return !(aFlags & ~eDOCUMENT);
}

Element*
nsIDocument::GetRootElement() const
{
  return (mCachedRootElement && mCachedRootElement->GetParentNode() == this) ?
         mCachedRootElement : GetRootElementInternal();
}

nsIContent*
nsIDocument::GetUnfocusedKeyEventTarget()
{
  return GetRootElement();
}

Element*
nsDocument::GetRootElementInternal() const
{
  // We invoke GetRootElement() immediately before the servo traversal, so we
  // should always have a cache hit from Servo.
  MOZ_ASSERT(NS_IsMainThread());

  // Loop backwards because any non-elements, such as doctypes and PIs
  // are likely to appear before the root element.
  uint32_t i;
  for (i = mChildren.ChildCount(); i > 0; --i) {
    nsIContent* child = mChildren.ChildAt(i - 1);
    if (child->IsElement()) {
      const_cast<nsDocument*>(this)->mCachedRootElement = child->AsElement();
      return child->AsElement();
    }
  }

  const_cast<nsDocument*>(this)->mCachedRootElement = nullptr;
  return nullptr;
}

nsIContent *
nsDocument::GetChildAt(uint32_t aIndex) const
{
  return mChildren.GetSafeChildAt(aIndex);
}

int32_t
nsDocument::IndexOf(const nsINode* aPossibleChild) const
{
  return mChildren.IndexOfChild(aPossibleChild);
}

uint32_t
nsDocument::GetChildCount() const
{
  return mChildren.ChildCount();
}

nsresult
nsDocument::InsertChildAt(nsIContent* aKid, uint32_t aIndex,
                          bool aNotify)
{
  if (aKid->IsElement() && GetRootElement()) {
    NS_WARNING("Inserting root element when we already have one");
    return NS_ERROR_DOM_HIERARCHY_REQUEST_ERR;
  }

  return doInsertChildAt(aKid, aIndex, aNotify, mChildren);
}

void
nsDocument::RemoveChildAt(uint32_t aIndex, bool aNotify)
{
  nsCOMPtr<nsIContent> oldKid = GetChildAt(aIndex);
  if (!oldKid) {
    return;
  }

  if (oldKid->IsElement()) {
    // Destroy the link map up front before we mess with the child list.
    DestroyElementMaps();
  }

  // Preemptively clear mCachedRootElement, since we may be about to remove it
  // from our child list, and we don't want to return this maybe-obsolete value
  // from any GetRootElement() calls that happen inside of doRemoveChildAt().
  // (NOTE: for this to be useful, doRemoveChildAt() must NOT trigger any
  // GetRootElement() calls until after it's removed the child from mChildren.
  // Any call before that point would restore this soon-to-be-obsolete cached
  // answer, and our clearing here would be fruitless.)
  mCachedRootElement = nullptr;
  doRemoveChildAt(aIndex, aNotify, oldKid, mChildren);
  MOZ_ASSERT(mCachedRootElement != oldKid,
             "Stale pointer in mCachedRootElement, after we tried to clear it "
             "(maybe somebody called GetRootElement() too early?)");
}

void
nsDocument::EnsureOnDemandBuiltInUASheet(StyleSheet* aSheet)
{
  if (mOnDemandBuiltInUASheets.Contains(aSheet)) {
    return;
  }
  BeginUpdate(UPDATE_STYLE);
  AddOnDemandBuiltInUASheet(aSheet);
  EndUpdate(UPDATE_STYLE);
}

void
nsDocument::AddOnDemandBuiltInUASheet(StyleSheet* aSheet)
{
  MOZ_ASSERT(!mOnDemandBuiltInUASheets.Contains(aSheet));
  MOZ_DIAGNOSTIC_ASSERT(aSheet->IsServo() == IsStyledByServo());

  // Prepend here so that we store the sheets in mOnDemandBuiltInUASheets in
  // the same order that they should end up in the style set.
  mOnDemandBuiltInUASheets.InsertElementAt(0, aSheet);

  if (aSheet->IsApplicable()) {
    // This is like |AddStyleSheetToStyleSets|, but for an agent sheet.
    nsCOMPtr<nsIPresShell> shell = GetShell();
    if (shell) {
      // Note that prepending here is necessary to make sure that html.css etc.
      // do not override Firefox OS/Mobile's content.css sheet. Maybe we should
      // have an insertion point to match the order of
      // nsDocumentViewer::CreateStyleSet though?
      shell->StyleSet()->PrependStyleSheet(SheetType::Agent, aSheet);
    }
  }

  NotifyStyleSheetAdded(aSheet, false);
}

int32_t
nsDocument::GetNumberOfStyleSheets() const
{
  return mStyleSheets.Length();
}

StyleSheet*
nsDocument::GetStyleSheetAt(int32_t aIndex) const
{
  return mStyleSheets.SafeElementAt(aIndex, nullptr);
}

int32_t
nsDocument::GetIndexOfStyleSheet(const StyleSheet* aSheet) const
{
  return mStyleSheets.IndexOf(aSheet);
}

void
nsDocument::AddStyleSheetToStyleSets(StyleSheet* aSheet)
{
  MOZ_DIAGNOSTIC_ASSERT(aSheet->IsServo() == IsStyledByServo());
  nsCOMPtr<nsIPresShell> shell = GetShell();
  if (shell) {
    shell->StyleSet()->AddDocStyleSheet(aSheet, this);
  }
}

#define DO_STYLESHEET_NOTIFICATION(className, type, memberName, argName)      \
  do {                                                                        \
    className##Init init;                                                     \
    init.mBubbles = true;                                                     \
    init.mCancelable = true;                                                  \
    init.mStylesheet = aSheet;                                                \
    init.memberName = argName;                                                \
                                                                              \
    RefPtr<className> event =                                               \
      className::Constructor(this, NS_LITERAL_STRING(type), init);            \
    event->SetTrusted(true);                                                  \
    event->SetTarget(this);                                                   \
    RefPtr<AsyncEventDispatcher> asyncDispatcher =                          \
      new AsyncEventDispatcher(this, event);                                  \
    asyncDispatcher->mOnlyChromeDispatch = true;                              \
    asyncDispatcher->PostDOMEvent();                                          \
  } while (0);

void
nsDocument::NotifyStyleSheetAdded(StyleSheet* aSheet, bool aDocumentSheet)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleSheetAdded, (aSheet, aDocumentSheet));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetChangeEvent,
                               "StyleSheetAdded",
                               mDocumentSheet,
                               aDocumentSheet);
  }
}

void
nsDocument::NotifyStyleSheetRemoved(StyleSheet* aSheet, bool aDocumentSheet)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleSheetRemoved, (aSheet, aDocumentSheet));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetChangeEvent,
                               "StyleSheetRemoved",
                               mDocumentSheet,
                               aDocumentSheet);
  }
}

void
nsDocument::AddStyleSheet(StyleSheet* aSheet)
{
  NS_PRECONDITION(aSheet, "null arg");
  MOZ_DIAGNOSTIC_ASSERT(aSheet->IsServo() == IsStyledByServo());
  mStyleSheets.AppendElement(aSheet);
  aSheet->SetAssociatedDocument(this, StyleSheet::OwnedByDocument);

  if (aSheet->IsApplicable()) {
    AddStyleSheetToStyleSets(aSheet);
  }

  NotifyStyleSheetAdded(aSheet, true);
}

void
nsDocument::RemoveStyleSheetFromStyleSets(StyleSheet* aSheet)
{
  nsCOMPtr<nsIPresShell> shell = GetShell();
  if (shell) {
    shell->StyleSet()->RemoveDocStyleSheet(aSheet);
  }
}

void
nsDocument::RemoveStyleSheet(StyleSheet* aSheet)
{
  NS_PRECONDITION(aSheet, "null arg");
  RefPtr<StyleSheet> sheet = aSheet; // hold ref so it won't die too soon

  if (!mStyleSheets.RemoveElement(aSheet)) {
    NS_ASSERTION(mInUnlinkOrDeletion, "stylesheet not found");
    return;
  }

  if (!mIsGoingAway) {
    if (aSheet->IsApplicable()) {
      RemoveStyleSheetFromStyleSets(aSheet);
    }

    NotifyStyleSheetRemoved(aSheet, true);
  }

  aSheet->ClearAssociatedDocument();
}

void
nsDocument::UpdateStyleSheets(nsTArray<RefPtr<StyleSheet>>& aOldSheets,
                              nsTArray<RefPtr<StyleSheet>>& aNewSheets)
{
  BeginUpdate(UPDATE_STYLE);

  // XXX Need to set the sheet on the ownernode, if any
  NS_PRECONDITION(aOldSheets.Length() == aNewSheets.Length(),
                  "The lists must be the same length!");
  int32_t count = aOldSheets.Length();

  RefPtr<StyleSheet> oldSheet;
  int32_t i;
  for (i = 0; i < count; ++i) {
    oldSheet = aOldSheets[i];

    // First remove the old sheet.
    NS_ASSERTION(oldSheet, "None of the old sheets should be null");
    int32_t oldIndex = mStyleSheets.IndexOf(oldSheet);
    RemoveStyleSheet(oldSheet);  // This does the right notifications

    // Now put the new one in its place.  If it's null, just ignore it.
    StyleSheet* newSheet = aNewSheets[i];
    if (newSheet) {
      MOZ_DIAGNOSTIC_ASSERT(newSheet->IsServo() == IsStyledByServo());
      mStyleSheets.InsertElementAt(oldIndex, newSheet);
      newSheet->SetAssociatedDocument(this, StyleSheet::OwnedByDocument);
      if (newSheet->IsApplicable()) {
        AddStyleSheetToStyleSets(newSheet);
      }

      NotifyStyleSheetAdded(newSheet, true);
    }
  }

  EndUpdate(UPDATE_STYLE);
}

void
nsDocument::InsertStyleSheetAt(StyleSheet* aSheet, int32_t aIndex)
{
  NS_PRECONDITION(aSheet, "null ptr");

  MOZ_DIAGNOSTIC_ASSERT(aSheet->IsServo() == IsStyledByServo());
  mStyleSheets.InsertElementAt(aIndex, aSheet);

  aSheet->SetAssociatedDocument(this, StyleSheet::OwnedByDocument);

  if (aSheet->IsApplicable()) {
    AddStyleSheetToStyleSets(aSheet);
  }

  NotifyStyleSheetAdded(aSheet, true);
}


void
nsDocument::SetStyleSheetApplicableState(StyleSheet* aSheet,
                                         bool aApplicable)
{
  NS_PRECONDITION(aSheet, "null arg");

  // If we're actually in the document style sheet list
  MOZ_DIAGNOSTIC_ASSERT(aSheet->IsServo() == IsStyledByServo());
  if (mStyleSheets.IndexOf(aSheet) != mStyleSheets.NoIndex) {
    if (aApplicable) {
      AddStyleSheetToStyleSets(aSheet);
    } else {
      RemoveStyleSheetFromStyleSets(aSheet);
    }
  }

  // We have to always notify, since this will be called for sheets
  // that are children of sheets in our style set, as well as some
  // sheets for HTMLEditor.

  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleSheetApplicableStateChanged, (aSheet));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetApplicableStateChangeEvent,
                               "StyleSheetApplicableStateChanged",
                               mApplicable,
                               aApplicable);
  }

  if (!mSSApplicableStateNotificationPending) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    nsCOMPtr<nsIRunnable> notification =
      NewRunnableMethod("nsDocument::NotifyStyleSheetApplicableStateChanged",
                        this,
                        &nsDocument::NotifyStyleSheetApplicableStateChanged);
    mSSApplicableStateNotificationPending =
      NS_SUCCEEDED(
        Dispatch(TaskCategory::Other, notification.forget()));
  }
}

void
nsDocument::NotifyStyleSheetApplicableStateChanged()
{
  mSSApplicableStateNotificationPending = false;
  nsCOMPtr<nsIObserverService> observerService =
    mozilla::services::GetObserverService();
  if (observerService) {
    observerService->NotifyObservers(static_cast<nsIDocument*>(this),
                                     "style-sheet-applicable-state-changed",
                                     nullptr);
  }
}

static SheetType
ConvertAdditionalSheetType(nsIDocument::additionalSheetType aType)
{
  switch(aType) {
    case nsIDocument::eAgentSheet:
      return SheetType::Agent;
    case nsIDocument::eUserSheet:
      return SheetType::User;
    case nsIDocument::eAuthorSheet:
      return SheetType::Doc;
    default:
      MOZ_ASSERT(false, "wrong type");
      // we must return something although this should never happen
      return SheetType::Count;
  }
}

static int32_t
FindSheet(const nsTArray<RefPtr<StyleSheet>>& aSheets, nsIURI* aSheetURI)
{
  for (int32_t i = aSheets.Length() - 1; i >= 0; i-- ) {
    bool bEqual;
    nsIURI* uri = aSheets[i]->GetSheetURI();

    if (uri && NS_SUCCEEDED(uri->Equals(aSheetURI, &bEqual)) && bEqual)
      return i;
  }

  return -1;
}

nsresult
nsDocument::LoadAdditionalStyleSheet(additionalSheetType aType,
                                     nsIURI* aSheetURI)
{
  NS_PRECONDITION(aSheetURI, "null arg");

  // Checking if we have loaded this one already.
  if (FindSheet(mAdditionalSheets[aType], aSheetURI) >= 0)
    return NS_ERROR_INVALID_ARG;

  // Loading the sheet sync.
  RefPtr<css::Loader> loader =
    new css::Loader(GetStyleBackendType(), GetDocGroup());

  css::SheetParsingMode parsingMode;
  switch (aType) {
    case nsIDocument::eAgentSheet:
      parsingMode = css::eAgentSheetFeatures;
      break;

    case nsIDocument::eUserSheet:
      parsingMode = css::eUserSheetFeatures;
      break;

    case nsIDocument::eAuthorSheet:
      parsingMode = css::eAuthorSheetFeatures;
      break;

    default:
      MOZ_CRASH("impossible value for aType");
  }

  RefPtr<StyleSheet> sheet;
  nsresult rv = loader->LoadSheetSync(aSheetURI, parsingMode, true, &sheet);
  NS_ENSURE_SUCCESS(rv, rv);

  sheet->SetAssociatedDocument(this, StyleSheet::OwnedByDocument);
  MOZ_ASSERT(sheet->IsApplicable());

  return AddAdditionalStyleSheet(aType, sheet);
}

nsresult
nsDocument::AddAdditionalStyleSheet(additionalSheetType aType, StyleSheet* aSheet)
{
  if (mAdditionalSheets[aType].Contains(aSheet))
    return NS_ERROR_INVALID_ARG;

  if (!aSheet->IsApplicable())
    return NS_ERROR_INVALID_ARG;

  mAdditionalSheets[aType].AppendElement(aSheet);

  BeginUpdate(UPDATE_STYLE);
  nsCOMPtr<nsIPresShell> shell = GetShell();
  if (shell) {
    SheetType type = ConvertAdditionalSheetType(aType);
    shell->StyleSet()->AppendStyleSheet(type, aSheet);
  }

  // Passing false, so documet.styleSheets.length will not be affected by
  // these additional sheets.
  NotifyStyleSheetAdded(aSheet, false);
  EndUpdate(UPDATE_STYLE);
  return NS_OK;
}

void
nsDocument::RemoveAdditionalStyleSheet(additionalSheetType aType, nsIURI* aSheetURI)
{
  MOZ_ASSERT(aSheetURI);

  nsTArray<RefPtr<StyleSheet>>& sheets = mAdditionalSheets[aType];

  int32_t i = FindSheet(mAdditionalSheets[aType], aSheetURI);
  if (i >= 0) {
    RefPtr<StyleSheet> sheetRef = sheets[i];
    sheets.RemoveElementAt(i);

    BeginUpdate(UPDATE_STYLE);
    if (!mIsGoingAway) {
      MOZ_ASSERT(sheetRef->IsApplicable());
      nsCOMPtr<nsIPresShell> shell = GetShell();
      if (shell) {
        SheetType type = ConvertAdditionalSheetType(aType);
        shell->StyleSet()->RemoveStyleSheet(type, sheetRef);
      }
    }

    // Passing false, so documet.styleSheets.length will not be affected by
    // these additional sheets.
    NotifyStyleSheetRemoved(sheetRef, false);
    EndUpdate(UPDATE_STYLE);

    sheetRef->ClearAssociatedDocument();
  }
}

StyleSheet*
nsDocument::GetFirstAdditionalAuthorSheet()
{
  return mAdditionalSheets[eAuthorSheet].SafeElementAt(0);
}

nsIGlobalObject*
nsDocument::GetScopeObject() const
{
  nsCOMPtr<nsIGlobalObject> scope(do_QueryReferent(mScopeObject));
  return scope;
}

void
nsDocument::SetScopeObject(nsIGlobalObject* aGlobal)
{
  mScopeObject = do_GetWeakReference(aGlobal);
  if (aGlobal) {
    mHasHadScriptHandlingObject = true;

    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aGlobal);
    if (window) {
      // We want to get the tabgroup unconditionally, such that we can make
      // certain that it is cached in the inner window early enough.
      mozilla::dom::TabGroup* tabgroup = window->TabGroup();
      // We should already have the principal, and now that we have been added to a
      // window, we should be able to join a DocGroup!
      nsAutoCString docGroupKey;
      nsresult rv =
        mozilla::dom::DocGroup::GetKey(NodePrincipal(), docGroupKey);
      if (mDocGroup) {
        if (NS_SUCCEEDED(rv)) {
          MOZ_RELEASE_ASSERT(mDocGroup->MatchesKey(docGroupKey));
        }
        MOZ_RELEASE_ASSERT(mDocGroup->GetTabGroup() == tabgroup);
      } else {
        mDocGroup = tabgroup->AddDocument(docGroupKey, this);
        MOZ_ASSERT(mDocGroup);
      }
    }
  }
}

static void
CheckIfContainsEMEContent(nsISupports* aSupports, void* aContainsEME)
{
  nsCOMPtr<nsIDOMHTMLMediaElement> domMediaElem(do_QueryInterface(aSupports));
  if (domMediaElem) {
    nsCOMPtr<nsIContent> content(do_QueryInterface(domMediaElem));
    MOZ_ASSERT(content, "aSupports is not a content");
    HTMLMediaElement* mediaElem = static_cast<HTMLMediaElement*>(content.get());
    bool* contains = static_cast<bool*>(aContainsEME);
    if (mediaElem->GetMediaKeys()) {
      *contains = true;
    }
  }
}

bool
nsDocument::ContainsEMEContent()
{
  bool containsEME = false;
  EnumerateActivityObservers(CheckIfContainsEMEContent,
                             static_cast<void*>(&containsEME));
  return containsEME;
}

static void
CheckIfContainsMSEContent(nsISupports* aSupports, void* aContainsMSE)
{
  nsCOMPtr<nsIDOMHTMLMediaElement> domMediaElem(do_QueryInterface(aSupports));
  if (domMediaElem) {
    nsCOMPtr<nsIContent> content(do_QueryInterface(domMediaElem));
    MOZ_ASSERT(content, "aSupports is not a content");
    HTMLMediaElement* mediaElem = static_cast<HTMLMediaElement*>(content.get());
    bool* contains = static_cast<bool*>(aContainsMSE);
    RefPtr<MediaSource> ms = mediaElem->GetMozMediaSourceObject();
    if (ms) {
      *contains = true;
    }
  }
}

bool
nsDocument::ContainsMSEContent()
{
  bool containsMSE = false;
  EnumerateActivityObservers(CheckIfContainsMSEContent,
                             static_cast<void*>(&containsMSE));
  return containsMSE;
}

static void
NotifyActivityChanged(nsISupports *aSupports, void *aUnused)
{
  nsCOMPtr<nsIDOMHTMLMediaElement> domMediaElem(do_QueryInterface(aSupports));
  if (domMediaElem) {
    nsCOMPtr<nsIContent> content(do_QueryInterface(domMediaElem));
    MOZ_ASSERT(content, "aSupports is not a content");
    HTMLMediaElement* mediaElem = static_cast<HTMLMediaElement*>(content.get());
    mediaElem->NotifyOwnerDocumentActivityChanged();
  }
  nsCOMPtr<nsIObjectLoadingContent> objectLoadingContent(do_QueryInterface(aSupports));
  if (objectLoadingContent) {
    nsObjectLoadingContent* olc = static_cast<nsObjectLoadingContent*>(objectLoadingContent.get());
    olc->NotifyOwnerDocumentActivityChanged();
  }
  nsCOMPtr<nsIDocumentActivity> objectDocumentActivity(do_QueryInterface(aSupports));
  if (objectDocumentActivity) {
    objectDocumentActivity->NotifyOwnerDocumentActivityChanged();
  }
}

void
nsIDocument::SetContainer(nsDocShell* aContainer)
{
  if (aContainer) {
    mDocumentContainer = aContainer;
  } else {
    mDocumentContainer = WeakPtr<nsDocShell>();
  }

  EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  if (!aContainer) {
    return;
  }

  // Get the Docshell
  if (aContainer->ItemType() == nsIDocShellTreeItem::typeContent) {
    // check if same type root
    nsCOMPtr<nsIDocShellTreeItem> sameTypeRoot;
    aContainer->GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot));
    NS_ASSERTION(sameTypeRoot, "No document shell root tree item from document shell tree item!");

    if (sameTypeRoot == aContainer) {
      static_cast<nsDocument*>(this)->SetIsTopLevelContentDocument(true);
    }

    static_cast<nsDocument*>(this)->SetIsContentDocument(true);
  }

  mAncestorPrincipals = aContainer->AncestorPrincipals();
}

nsISupports*
nsIDocument::GetContainer() const
{
  return static_cast<nsIDocShell*>(mDocumentContainer);
}

void
nsDocument::SetScriptGlobalObject(nsIScriptGlobalObject *aScriptGlobalObject)
{
#ifdef DEBUG
  {
    nsCOMPtr<nsPIDOMWindowInner> win(do_QueryInterface(aScriptGlobalObject));

    NS_ASSERTION(!win || win->IsInnerWindow(),
                 "Script global object must be an inner window!");
  }
#endif
  MOZ_ASSERT(aScriptGlobalObject || !mAnimationController ||
             mAnimationController->IsPausedByType(
               nsSMILTimeContainer::PAUSE_PAGEHIDE |
               nsSMILTimeContainer::PAUSE_BEGIN),
             "Clearing window pointer while animations are unpaused");

  if (mScriptGlobalObject && !aScriptGlobalObject) {
    // We're detaching from the window.  We need to grab a pointer to
    // our layout history state now.
    mLayoutHistoryState = GetLayoutHistoryState();

    // Also make sure to remove our onload blocker now if we haven't done it yet
    if (mOnloadBlockCount != 0) {
      nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
      if (loadGroup) {
        loadGroup->RemoveRequest(mOnloadBlocker, nullptr, NS_OK);
      }
    }

    using mozilla::dom::workers::ServiceWorkerManager;
    RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
    if (swm) {
      ErrorResult error;
      if (swm->IsControlled(this, error)) {
        imgLoader* loader = nsContentUtils::GetImgLoaderForDocument(this);
        if (loader) {
          loader->ClearCacheForControlledDocument(this);
        }

        // We may become controlled again if this document comes back out
        // of bfcache.  Clear our state to allow that to happen.  Only
        // clear this flag if we are actually controlled, though, so pages
        // that were force reloaded don't become controlled when they
        // come out of bfcache.
        mMaybeServiceWorkerControlled = false;
      }
      swm->MaybeStopControlling(this);
    }

    // Remove ourself from the list of clients.  We only register
    // content principal documents in this list.
    if (!nsContentUtils::IsSystemPrincipal(GetPrincipal()) &&
        !GetPrincipal()->GetIsNullPrincipal()) {
      nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
      if (os) {
        os->RemoveObserver(this, "service-worker-get-client");
      }
    }

  } else if (!mScriptGlobalObject && aScriptGlobalObject &&
             mDocumentContainer && GetChannel() &&
             !nsContentUtils::IsSystemPrincipal(GetPrincipal()) &&
             !GetPrincipal()->GetIsNullPrincipal()) {
    // This document is being activated.  Register it in the list of
    // clients.  We only do this for content principal documents
    // since we can never observe system or null principals.
    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
    if (os) {
      os->AddObserver(this, "service-worker-get-client", /* ownsWeak */ false);
    }
  }

  // BlockOnload() might be called before mScriptGlobalObject is set.
  // We may need to add the blocker once mScriptGlobalObject is set.
  bool needOnloadBlocker = !mScriptGlobalObject && aScriptGlobalObject;

  mScriptGlobalObject = aScriptGlobalObject;

  if (needOnloadBlocker) {
    EnsureOnloadBlocker();
  }

  UpdateFrameRequestCallbackSchedulingState();

  if (aScriptGlobalObject) {
    // Go back to using the docshell for the layout history state
    mLayoutHistoryState = nullptr;
    SetScopeObject(aScriptGlobalObject);
    mHasHadDefaultView = true;
#ifdef DEBUG
    if (!mWillReparent) {
      // We really shouldn't have a wrapper here but if we do we need to make sure
      // it has the correct parent.
      JSObject *obj = GetWrapperPreserveColor();
      if (obj) {
        JSObject *newScope = aScriptGlobalObject->GetGlobalJSObject();
        NS_ASSERTION(js::GetGlobalForObjectCrossCompartment(obj) == newScope,
                     "Wrong scope, this is really bad!");
      }
    }
#endif

    if (mAllowDNSPrefetch) {
      nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
      if (docShell) {
#ifdef DEBUG
        nsCOMPtr<nsIWebNavigation> webNav =
          do_GetInterface(aScriptGlobalObject);
        NS_ASSERTION(SameCOMIdentity(webNav, docShell),
                     "Unexpected container or script global?");
#endif
        bool allowDNSPrefetch;
        docShell->GetAllowDNSPrefetch(&allowDNSPrefetch);
        mAllowDNSPrefetch = allowDNSPrefetch;
      }
    }

    // If we are set in a window that is already focused we should remember this
    // as the time the document gained focus.
    bool focused = false;
    Unused << HasFocus(&focused);
    if (focused) {
      SetLastFocusTime(TimeStamp::Now());
    }
  }

  // Remember the pointer to our window (or lack there of), to avoid
  // having to QI every time it's asked for.
  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(mScriptGlobalObject);
  mWindow = window;

  // Now that we know what our window is, we can flush the CSP errors to the
  // Web Console. We are flushing all messages that occured and were stored
  // in the queue prior to this point.
  nsCOMPtr<nsIContentSecurityPolicy> csp;
  NodePrincipal()->GetCsp(getter_AddRefs(csp));
  if (csp) {
    static_cast<nsCSPContext*>(csp.get())->flushConsoleMessages();
  }

  nsCOMPtr<nsIHttpChannelInternal> internalChannel =
    do_QueryInterface(GetChannel());
  if (internalChannel) {
    nsCOMArray<nsISecurityConsoleMessage> messages;
    DebugOnly<nsresult> rv = internalChannel->TakeAllSecurityMessages(messages);
    MOZ_ASSERT(NS_SUCCEEDED(rv));
    SendToConsole(messages);
  }

  // Set our visibility state, but do not fire the event.  This is correct
  // because either we're coming out of bfcache (in which case IsVisible() will
  // still test false at this point and no state change will happen) or we're
  // doing the initial document load and don't want to fire the event for this
  // change.
  dom::VisibilityState oldState = mVisibilityState;
  mVisibilityState = GetVisibilityState();
  // When the visibility is changed, notify it to observers.
  // Some observers need the notification, for example HTMLMediaElement uses
  // it to update internal media resource allocation.
  // When video is loaded via VideoDocument, HTMLMediaElement and MediaDecoder
  // creation are already done before nsDocument::SetScriptGlobalObject() call.
  // MediaDecoder decides whether starting decoding is decided based on
  // document's visibility. When the MediaDecoder is created,
  // nsDocument::SetScriptGlobalObject() is not yet called and document is
  // hidden state. Therefore the MediaDecoder decides that decoding is
  // not yet necessary. But soon after nsDocument::SetScriptGlobalObject()
  // call, the document becomes not hidden. At the time, MediaDecoder needs
  // to know it and needs to start updating decoding.
  if (oldState != mVisibilityState) {
    EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  }

  // The global in the template contents owner document should be the same.
  if (mTemplateContentsOwner && mTemplateContentsOwner != this) {
    mTemplateContentsOwner->SetScriptGlobalObject(aScriptGlobalObject);
  }

  if (!mMaybeServiceWorkerControlled && mDocumentContainer && mScriptGlobalObject && GetChannel()) {
    nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
    uint32_t loadType;
    docShell->GetLoadType(&loadType);

    // If we are shift-reloaded, don't associate with a ServiceWorker.
    if (IsForceReloadType(loadType)) {
      NS_WARNING("Page was shift reloaded, skipping ServiceWorker control");
      return;
    }

    nsCOMPtr<nsIServiceWorkerManager> swm = mozilla::services::GetServiceWorkerManager();
    if (swm) {
      // If this document is being resurrected from the bfcache, then we may
      // already have a document ID.  In that case reuse the same ID.  Otherwise
      // get our document ID from the docshell.
      nsString documentId(GetId());
      if (documentId.IsEmpty()) {
        static_cast<nsDocShell*>(docShell.get())->GetInterceptedDocumentId(documentId);
      }

      swm->MaybeStartControlling(this, documentId);
      mMaybeServiceWorkerControlled = true;
    }
  }
}

nsIScriptGlobalObject*
nsDocument::GetScriptHandlingObjectInternal() const
{
  MOZ_ASSERT(!mScriptGlobalObject,
             "Do not call this when mScriptGlobalObject is set!");
  if (mHasHadDefaultView) {
    return nullptr;
  }

  nsCOMPtr<nsIScriptGlobalObject> scriptHandlingObject =
    do_QueryReferent(mScopeObject);
  nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(scriptHandlingObject);
  if (win) {
    nsPIDOMWindowOuter* outer = win->GetOuterWindow();
    if (!outer || outer->GetCurrentInnerWindow() != win) {
      NS_WARNING("Wrong inner/outer window combination!");
      return nullptr;
    }
  }
  return scriptHandlingObject;
}
void
nsDocument::SetScriptHandlingObject(nsIScriptGlobalObject* aScriptObject)
{
  NS_ASSERTION(!mScriptGlobalObject ||
               mScriptGlobalObject == aScriptObject,
               "Wrong script object!");
  if (aScriptObject) {
    SetScopeObject(aScriptObject);
    mHasHadDefaultView = false;
  }
}

nsPIDOMWindowOuter*
nsDocument::GetWindowInternal() const
{
  MOZ_ASSERT(!mWindow, "This should not be called when mWindow is not null!");
  // Let's use mScriptGlobalObject. Even if the document is already removed from
  // the docshell, the outer window might be still obtainable from the it.
  nsCOMPtr<nsPIDOMWindowOuter> win;
  if (mRemovedFromDocShell) {
    // The docshell returns the outer window we are done.
    nsCOMPtr<nsIDocShell> kungFuDeathGrip(mDocumentContainer);
    if (kungFuDeathGrip) {
      win = kungFuDeathGrip->GetWindow();
    }
  } else {
    if (nsCOMPtr<nsPIDOMWindowInner> inner = do_QueryInterface(mScriptGlobalObject)) {
      // mScriptGlobalObject is always the inner window, let's get the outer.
      win = inner->GetOuterWindow();
    }
  }

  return win;
}

ScriptLoader*
nsDocument::ScriptLoader()
{
  return mScriptLoader;
}

bool
nsDocument::InternalAllowXULXBL()
{
  if (nsContentUtils::AllowXULXBLForPrincipal(NodePrincipal())) {
    mAllowXULXBL = eTriTrue;
    return true;
  }

  mAllowXULXBL = eTriFalse;
  return false;
}

// Note: We don't hold a reference to the document observer; we assume
// that it has a live reference to the document.
void
nsDocument::AddObserver(nsIDocumentObserver* aObserver)
{
  NS_ASSERTION(mObservers.IndexOf(aObserver) == nsTArray<int>::NoIndex,
               "Observer already in the list");
  mObservers.AppendElement(aObserver);
  AddMutationObserver(aObserver);
}

bool
nsDocument::RemoveObserver(nsIDocumentObserver* aObserver)
{
  // If we're in the process of destroying the document (and we're
  // informing the observers of the destruction), don't remove the
  // observers from the list. This is not a big deal, since we
  // don't hold a live reference to the observers.
  if (!mInDestructor) {
    RemoveMutationObserver(aObserver);
    return mObservers.RemoveElement(aObserver);
  }

  return mObservers.Contains(aObserver);
}

void
nsDocument::MaybeEndOutermostXBLUpdate()
{
  // Only call BindingManager()->EndOutermostUpdate() when
  // we're not in an update and it is safe to run scripts.
  if (mUpdateNestLevel == 0 && mInXBLUpdate) {
    if (nsContentUtils::IsSafeToRunScript()) {
      mInXBLUpdate = false;
      BindingManager()->EndOutermostUpdate();
    } else if (!mInDestructor) {
      if (!mMaybeEndOutermostXBLUpdateRunner) {
        mMaybeEndOutermostXBLUpdateRunner =
          NewRunnableMethod("nsDocument::MaybeEndOutermostXBLUpdate",
                            this,
                            &nsDocument::MaybeEndOutermostXBLUpdate);
      }
      nsContentUtils::AddScriptRunner(mMaybeEndOutermostXBLUpdateRunner);
    }
  }
}

void
nsDocument::BeginUpdate(nsUpdateType aUpdateType)
{
  // If the document is going away, then it's probably okay to do things to it
  // in the wrong DocGroup. We're unlikely to run JS or do anything else
  // observable at this point. We reach this point when cycle collecting a
  // <link> element and the unlink code removes a style sheet.
  if (mDocGroup && !mIsGoingAway && !mInUnlinkOrDeletion && !mIgnoreDocGroupMismatches) {
    mDocGroup->ValidateAccess();
  }

  if (mUpdateNestLevel == 0 && !mInXBLUpdate) {
    mInXBLUpdate = true;
    BindingManager()->BeginOutermostUpdate();
  }

  ++mUpdateNestLevel;
  nsContentUtils::AddScriptBlocker();
  NS_DOCUMENT_NOTIFY_OBSERVERS(BeginUpdate, (this, aUpdateType));
}

void
nsDocument::EndUpdate(nsUpdateType aUpdateType)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(EndUpdate, (this, aUpdateType));

  nsContentUtils::RemoveScriptBlocker();

  --mUpdateNestLevel;

  // This set of updates may have created XBL bindings.  Let the
  // binding manager know we're done.
  MaybeEndOutermostXBLUpdate();

  MaybeInitializeFinalizeFrameLoaders();
}

void
nsDocument::BeginLoad()
{
  MOZ_ASSERT(!mDidCallBeginLoad);
  mDidCallBeginLoad = true;

  // Block onload here to prevent having to deal with blocking and
  // unblocking it while we know the document is loading.
  BlockOnload();
  mDidFireDOMContentLoaded = false;
  BlockDOMContentLoaded();

  if (mScriptLoader) {
    mScriptLoader->BeginDeferringScripts();
  }

  NS_DOCUMENT_NOTIFY_OBSERVERS(BeginLoad, (this));
}

void
nsDocument::ReportEmptyGetElementByIdArg()
{
  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                  NS_LITERAL_CSTRING("DOM"), this,
                                  nsContentUtils::eDOM_PROPERTIES,
                                  "EmptyGetElementByIdParam");
}

Element*
nsDocument::GetElementById(const nsAString& aElementId)
{
  if (!CheckGetElementByIdArg(aElementId)) {
    return nullptr;
  }

  nsIdentifierMapEntry *entry = mIdentifierMap.GetEntry(aElementId);
  return entry ? entry->GetIdElement() : nullptr;
}

const nsTArray<Element*>*
nsDocument::GetAllElementsForId(const nsAString& aElementId) const
{
  if (aElementId.IsEmpty()) {
    return nullptr;
  }

  nsIdentifierMapEntry *entry = mIdentifierMap.GetEntry(aElementId);
  return entry ? &entry->GetIdElements() : nullptr;
}

NS_IMETHODIMP
nsDocument::GetElementById(const nsAString& aId, nsIDOMElement** aReturn)
{
  Element *content = GetElementById(aId);
  if (content) {
    return CallQueryInterface(content, aReturn);
  }

  *aReturn = nullptr;

  return NS_OK;
}

Element*
nsDocument::AddIDTargetObserver(nsIAtom* aID, IDTargetObserver aObserver,
                                void* aData, bool aForImage)
{
  nsDependentAtomString id(aID);

  if (!CheckGetElementByIdArg(id))
    return nullptr;

  nsIdentifierMapEntry* entry = mIdentifierMap.PutEntry(aID);
  NS_ENSURE_TRUE(entry, nullptr);

  entry->AddContentChangeCallback(aObserver, aData, aForImage);
  return aForImage ? entry->GetImageIdElement() : entry->GetIdElement();
}

void
nsDocument::RemoveIDTargetObserver(nsIAtom* aID, IDTargetObserver aObserver,
                                   void* aData, bool aForImage)
{
  nsDependentAtomString id(aID);

  if (!CheckGetElementByIdArg(id))
    return;

  nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aID);
  if (!entry) {
    return;
  }

  entry->RemoveContentChangeCallback(aObserver, aData, aForImage);
}

NS_IMETHODIMP
nsDocument::MozSetImageElement(const nsAString& aImageElementId,
                               nsIDOMElement* aImageElement)
{
  nsCOMPtr<Element> el = do_QueryInterface(aImageElement);
  MozSetImageElement(aImageElementId, el);
  return NS_OK;
}

void
nsDocument::MozSetImageElement(const nsAString& aImageElementId,
                               Element* aElement)
{
  if (aImageElementId.IsEmpty())
    return;

  // Hold a script blocker while calling SetImageElement since that can call
  // out to id-observers
  nsAutoScriptBlocker scriptBlocker;

  nsIdentifierMapEntry *entry = mIdentifierMap.PutEntry(aImageElementId);
  if (entry) {
    entry->SetImageElement(aElement);
    if (entry->IsEmpty()) {
      mIdentifierMap.RemoveEntry(entry);
    }
  }
}

Element*
nsDocument::LookupImageElement(const nsAString& aId)
{
  if (aId.IsEmpty())
    return nullptr;

  nsIdentifierMapEntry *entry = mIdentifierMap.GetEntry(aId);
  return entry ? entry->GetImageIdElement() : nullptr;
}

void
nsDocument::DispatchContentLoadedEvents()
{
  // If you add early returns from this method, make sure you're
  // calling UnblockOnload properly.

  // Unpin references to preloaded images
  mPreloadingImages.Clear();

  // DOM manipulation after content loaded should not care if the element
  // came from the preloader.
  mPreloadedPreconnects.Clear();

  if (mTiming) {
    mTiming->NotifyDOMContentLoadedStart(nsIDocument::GetDocumentURI());
  }

  // Dispatch observer notification to notify observers document is interactive.
  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
  if (os) {
    nsIPrincipal *principal = GetPrincipal();
    os->NotifyObservers(static_cast<nsIDocument*>(this),
                        nsContentUtils::IsSystemPrincipal(principal) ?
                          "chrome-document-interactive" :
                          "content-document-interactive",
                        nullptr);
  }

  // Fire a DOM event notifying listeners that this document has been
  // loaded (excluding images and other loads initiated by this
  // document).
  nsContentUtils::DispatchTrustedEvent(this, static_cast<nsIDocument*>(this),
                                       NS_LITERAL_STRING("DOMContentLoaded"),
                                       true, false);

  RefPtr<TimelineConsumers> timelines = TimelineConsumers::Get();
  nsIDocShell* docShell = this->GetDocShell();

  if (timelines && timelines->HasConsumer(docShell)) {
    timelines->AddMarkerForDocShell(docShell,
      MakeUnique<DocLoadingTimelineMarker>("document::DOMContentLoaded"));
  }

  if (mTiming) {
    mTiming->NotifyDOMContentLoadedEnd(nsIDocument::GetDocumentURI());
  }

  // If this document is a [i]frame, fire a DOMFrameContentLoaded
  // event on all parent documents notifying that the HTML (excluding
  // other external files such as images and stylesheets) in a frame
  // has finished loading.

  // target_frame is the [i]frame element that will be used as the
  // target for the event. It's the [i]frame whose content is done
  // loading.
  nsCOMPtr<EventTarget> target_frame;

  if (mParentDocument) {
    target_frame = mParentDocument->FindContentForSubDocument(this);
  }

  if (target_frame) {
    nsCOMPtr<nsIDocument> parent = mParentDocument;
    do {
      nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(parent);

      nsCOMPtr<nsIDOMEvent> event;
      if (domDoc) {
        domDoc->CreateEvent(NS_LITERAL_STRING("Events"),
                            getter_AddRefs(event));

      }

      if (event) {
        event->InitEvent(NS_LITERAL_STRING("DOMFrameContentLoaded"), true,
                         true);

        event->SetTarget(target_frame);
        event->SetTrusted(true);

        // To dispatch this event we must manually call
        // EventDispatcher::Dispatch() on the ancestor document since the
        // target is not in the same document, so the event would never reach
        // the ancestor document if we used the normal event
        // dispatching code.

        WidgetEvent* innerEvent = event->WidgetEventPtr();
        if (innerEvent) {
          nsEventStatus status = nsEventStatus_eIgnore;

          nsIPresShell *shell = parent->GetShell();
          if (shell) {
            RefPtr<nsPresContext> context = shell->GetPresContext();

            if (context) {
              EventDispatcher::Dispatch(parent, context, innerEvent, event,
                                        &status);
            }
          }
        }
      }

      parent = parent->GetParentDocument();
    } while (parent);
  }

  // If the document has a manifest attribute, fire a MozApplicationManifest
  // event.
  Element* root = GetRootElement();
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::manifest)) {
    nsContentUtils::DispatchChromeEvent(this, static_cast<nsIDocument*>(this),
                                        NS_LITERAL_STRING("MozApplicationManifest"),
                                        true, true);
  }

  if (mMaybeServiceWorkerControlled) {
    using mozilla::dom::workers::ServiceWorkerManager;
    RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
    if (swm) {
      swm->MaybeCheckNavigationUpdate(this);
    }
  }

  UnblockOnload(true);
}

void
nsDocument::EndLoad()
{
  // EndLoad may have been called without a matching call to BeginLoad, in the
  // case of a failed parse (for example, due to timeout). In such a case, we
  // still want to execute part of this code to do appropriate cleanup, but we
  // gate part of it because it is intended to match 1-for-1 with calls to
  // BeginLoad. We have an explicit flag bit for this purpose, since it's
  // complicated and error prone to derive this condition from other related
  // flags that can be manipulated outside of a BeginLoad/EndLoad pair.

  // Part 1: Code that always executes to cleanup end of parsing, whether
  // that parsing was successful or not.

  // Drop the ref to our parser, if any, but keep hold of the sink so that we
  // can flush it from FlushPendingNotifications as needed.  We might have to
  // do that to get a StartLayout() to happen.
  if (mParser) {
    mWeakSink = do_GetWeakReference(mParser->GetContentSink());
    mParser = nullptr;
  }

  NS_DOCUMENT_NOTIFY_OBSERVERS(EndLoad, (this));

  // Part 2: Code that only executes when this EndLoad matches a BeginLoad.

  if (!mDidCallBeginLoad) {
    return;
  }
  mDidCallBeginLoad = false;

  UnblockDOMContentLoaded();
}

void
nsDocument::UnblockDOMContentLoaded()
{
  MOZ_ASSERT(mBlockDOMContentLoaded);
  if (--mBlockDOMContentLoaded != 0 || mDidFireDOMContentLoaded) {
    return;
  }

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p UnblockDOMContentLoaded", this));

  mDidFireDOMContentLoaded = true;

  MOZ_ASSERT(mReadyState == READYSTATE_INTERACTIVE);
  if (!mSynchronousDOMContentLoaded) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    nsCOMPtr<nsIRunnable> ev =
      NewRunnableMethod("nsDocument::DispatchContentLoadedEvents",
                        this,
                        &nsDocument::DispatchContentLoadedEvents);
    Dispatch(TaskCategory::Other, ev.forget());
  } else {
    DispatchContentLoadedEvents();
  }
}

void
nsDocument::ContentStateChanged(nsIContent* aContent, EventStates aStateMask)
{
  NS_PRECONDITION(!nsContentUtils::IsSafeToRunScript(),
                  "Someone forgot a scriptblocker");
  NS_DOCUMENT_NOTIFY_OBSERVERS(ContentStateChanged,
                               (this, aContent, aStateMask));
}

void
nsDocument::DocumentStatesChanged(EventStates aStateMask)
{
  // Invalidate our cached state.
  mGotDocumentState &= ~aStateMask;
  mDocumentState &= ~aStateMask;

  NS_DOCUMENT_NOTIFY_OBSERVERS(DocumentStatesChanged, (this, aStateMask));
}

void
nsDocument::StyleRuleChanged(StyleSheet* aSheet,
                             css::Rule* aStyleRule)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleRuleChanged, (aSheet, aStyleRule));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent,
                               "StyleRuleChanged",
                               mRule,
                               aStyleRule);
  }
}

void
nsDocument::StyleRuleAdded(StyleSheet* aSheet,
                           css::Rule* aStyleRule)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleRuleAdded, (aSheet, aStyleRule));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent,
                               "StyleRuleAdded",
                               mRule,
                               aStyleRule);
  }
}

void
nsDocument::StyleRuleRemoved(StyleSheet* aSheet,
                             css::Rule* aStyleRule)
{
  NS_DOCUMENT_NOTIFY_OBSERVERS(StyleRuleRemoved, (aSheet, aStyleRule));

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent,
                               "StyleRuleRemoved",
                               mRule,
                               aStyleRule);
  }
}

#undef DO_STYLESHEET_NOTIFICATION

already_AddRefed<AnonymousContent>
nsIDocument::InsertAnonymousContent(Element& aElement, ErrorResult& aRv)
{
  nsIPresShell* shell = GetShell();
  if (!shell || !shell->GetCanvasFrame()) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  nsAutoScriptBlocker scriptBlocker;
  nsCOMPtr<Element> container = shell->GetCanvasFrame()
                                     ->GetCustomContentContainer();
  if (!container) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  // Clone the node to avoid returning a direct reference
  nsCOMPtr<nsINode> clonedElement = aElement.CloneNode(true, aRv);
  if (aRv.Failed()) {
    return nullptr;
  }

  // Insert the element into the container
  nsresult rv;
  rv = container->AppendChildTo(clonedElement->AsContent(), true);
  if (NS_FAILED(rv)) {
    return nullptr;
  }

  RefPtr<AnonymousContent> anonymousContent =
    new AnonymousContent(clonedElement->AsElement());
  mAnonymousContents.AppendElement(anonymousContent);

  shell->GetCanvasFrame()->ShowCustomContentContainer();

  return anonymousContent.forget();
}

void
nsIDocument::RemoveAnonymousContent(AnonymousContent& aContent,
                                    ErrorResult& aRv)
{
  nsIPresShell* shell = GetShell();
  if (!shell || !shell->GetCanvasFrame()) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return;
  }

  nsAutoScriptBlocker scriptBlocker;
  nsCOMPtr<Element> container = shell->GetCanvasFrame()
                                     ->GetCustomContentContainer();
  if (!container) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return;
  }

  // Iterate over mAnonymousContents to find and remove the given node.
  for (size_t i = 0, len = mAnonymousContents.Length(); i < len; ++i) {
    if (mAnonymousContents[i] == &aContent) {
      // Get the node from the customContent
      nsCOMPtr<Element> node = aContent.GetContentNode();

      // Remove the entry in mAnonymousContents
      mAnonymousContents.RemoveElementAt(i);

      // Remove the node from its container
      container->RemoveChild(*node, aRv);
      if (aRv.Failed()) {
        return;
      }

      break;
    }
  }
  if (mAnonymousContents.IsEmpty()) {
    shell->GetCanvasFrame()->HideCustomContentContainer();
  }
}

Element*
nsIDocument::GetAnonRootIfInAnonymousContentContainer(nsINode* aNode) const
{
  if (!aNode->IsInNativeAnonymousSubtree()) {
    return nullptr;
  }

  nsIPresShell* shell = GetShell();
  if (!shell || !shell->GetCanvasFrame()) {
    return nullptr;
  }

  nsAutoScriptBlocker scriptBlocker;
  nsCOMPtr<Element> customContainer = shell->GetCanvasFrame()
                                           ->GetCustomContentContainer();
  if (!customContainer) {
    return nullptr;
  }

  // An arbitrary number of elements can be inserted as children of the custom
  // container frame.  We want the one that was added that contains aNode, so
  // we need to keep track of the last child separately using |child| here.
  nsINode* child = aNode;
  nsINode* parent = aNode->GetParentNode();
  while (parent && parent->IsInNativeAnonymousSubtree()) {
    if (parent == customContainer) {
      return child->IsElement() ? child->AsElement() : nullptr;
    }
    child = parent;
    parent = child->GetParentNode();
  }
  return nullptr;
}

//
// nsIDOMDocument interface
//
DocumentType*
nsIDocument::GetDoctype() const
{
  for (nsIContent* child = GetFirstChild();
       child;
       child = child->GetNextSibling()) {
    if (child->NodeType() == nsIDOMNode::DOCUMENT_TYPE_NODE) {
      return static_cast<DocumentType*>(child);
    }
  }
  return nullptr;
}

NS_IMETHODIMP
nsDocument::GetDoctype(nsIDOMDocumentType** aDoctype)
{
  MOZ_ASSERT(aDoctype);
  nsCOMPtr<nsIDOMDocumentType> doctype = nsIDocument::GetDoctype();
  doctype.forget(aDoctype);
  return NS_OK;
}

NS_IMETHODIMP
nsDocument::GetImplementation(nsIDOMDOMImplementation** aImplementation)
{
  ErrorResult rv;
  *aImplementation = GetImplementation(rv);
  if (rv.Failed()) {
    MOZ_ASSERT(!*aImplementation);
    return rv.StealNSResult();
  }
  NS_ADDREF(*aImplementation);
  return NS_OK;
}

DOMImplementation*
nsDocument::GetImplementation(ErrorResult& rv)
{
  if (!mDOMImplementation) {
    nsCOMPtr<nsIURI> uri;
    NS_NewURI(getter_AddRefs(uri), "about:blank");
    if (!uri) {
      rv.Throw(NS_ERROR_OUT_OF_MEMORY);
      return nullptr;
    }
    bool hasHadScriptObject = true;
    nsIScriptGlobalObject* scriptObject =
      GetScriptHandlingObject(hasHadScriptObject);
    if (!scriptObject && hasHadScriptObject) {
      rv.Throw(NS_ERROR_UNEXPECTED);
      return nullptr;
    }
    mDOMImplementation = new DOMImplementation(this,
      scriptObject ? scriptObject : GetScopeObject(), uri, uri);
  }

  return mDOMImplementation;
}

NS_IMETHODIMP
nsDocument::GetDocumentElement(nsIDOMElement** aDocumentElement)
{
  NS_ENSURE_ARG_POINTER(aDocumentElement);

  Element* root = GetRootElement();
  if (root) {
    return CallQueryInterface(root, aDocumentElement);
  }

  *aDocumentElement = nullptr;

  return NS_OK;
}

NS_IMETHODIMP
nsDocument::CreateElement(const nsAString& aTagName,
                          nsIDOMElement** aReturn)
{
  *aReturn = nullptr;
  ErrorResult rv;
  ElementCreationOptionsOrString options;

  options.SetAsString();
  nsCOMPtr<Element> element = CreateElement(aTagName, options, rv);
  NS_ENSURE_FALSE(rv.Failed(), rv.StealNSResult());
  return CallQueryInterface(element, aReturn);
}

bool IsLowercaseASCII(const nsAString& aValue)
{
  int32_t len = aValue.Length();
  for (int32_t i = 0; i < len; ++i) {
    char16_t c = aValue[i];
    if (!(0x0061 <= (c) && ((c) <= 0x007a))) {
      return false;
    }
  }
  return true;
}

already_AddRefed<mozilla::dom::CustomElementRegistry>
nsDocument::GetCustomElementRegistry()
{
  nsAutoString contentType;
  GetContentType(contentType);
  if (!IsHTMLDocument() &&
      !contentType.EqualsLiteral("application/xhtml+xml")) {
    return nullptr;
  }

  nsCOMPtr<nsPIDOMWindowInner> window(
    do_QueryInterface(mScriptGlobalObject ? mScriptGlobalObject
                                          : GetScopeObject()));
  if (!window) {
    return nullptr;
  }

  RefPtr<CustomElementRegistry> registry = window->CustomElements();
  if (!registry) {
    return nullptr;
  }

  return registry.forget();
}

// We only support pseudo-elements with two colons in this function.
static CSSPseudoElementType
GetPseudoElementType(const nsString& aString, ErrorResult& aRv)
{
  MOZ_ASSERT(!aString.IsEmpty(), "GetPseudoElementType aString should be non-null");
  if (aString.Length() <= 2 || aString[0] != ':' || aString[1] != ':') {
    aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
    return CSSPseudoElementType::NotPseudo;
  }
  nsCOMPtr<nsIAtom> pseudo = NS_Atomize(Substring(aString, 1));
  return nsCSSPseudoElements::GetPseudoType(pseudo,
      nsCSSProps::EnabledState::eInUASheets);
}

already_AddRefed<Element>
nsDocument::CreateElement(const nsAString& aTagName,
                          const ElementCreationOptionsOrString& aOptions,
                          ErrorResult& rv)
{
  rv = nsContentUtils::CheckQName(aTagName, false);
  if (rv.Failed()) {
    return nullptr;
  }

  bool needsLowercase = IsHTMLDocument() && !IsLowercaseASCII(aTagName);
  nsAutoString lcTagName;
  if (needsLowercase) {
    nsContentUtils::ASCIIToLower(aTagName, lcTagName);
  }

  const nsString* is = nullptr;
  CSSPseudoElementType pseudoType = CSSPseudoElementType::NotPseudo;
  if (aOptions.IsElementCreationOptions()) {
    const ElementCreationOptions& options =
      aOptions.GetAsElementCreationOptions();

    if (CustomElementRegistry::IsCustomElementEnabled() &&
        options.mIs.WasPassed()) {
      is = &options.mIs.Value();
    }

    // Check 'pseudo' and throw an exception if it's not one allowed
    // with CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC.
    if (options.mPseudo.WasPassed()) {
      pseudoType = GetPseudoElementType(options.mPseudo.Value(), rv);
      if (rv.Failed() ||
          pseudoType == CSSPseudoElementType::NotPseudo ||
          !nsCSSPseudoElements::PseudoElementIsJSCreatedNAC(pseudoType)) {
        rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
        return nullptr;
      }
    }
  }

  RefPtr<Element> elem = CreateElem(
    needsLowercase ? lcTagName : aTagName, nullptr, mDefaultElementType, is);

  if (pseudoType != CSSPseudoElementType::NotPseudo) {
    elem->SetPseudoElementType(pseudoType);
  }

  return elem.forget();
}

NS_IMETHODIMP
nsDocument::CreateElementNS(const nsAString& aNamespaceURI,
                            const nsAString& aQualifiedName,
                            nsIDOMElement** aReturn)
{
  *aReturn = nullptr;
  ElementCreationOptionsOrString options;

  options.SetAsString();
  ErrorResult rv;
  nsCOMPtr<Element> element =
    CreateElementNS(aNamespaceURI, aQualifiedName, options, rv);
  NS_ENSURE_FALSE(rv.Failed(), rv.StealNSResult());
  return CallQueryInterface(element, aReturn);
}

already_AddRefed<Element>
nsDocument::CreateElementNS(const nsAString& aNamespaceURI,
                            const nsAString& aQualifiedName,
                            const ElementCreationOptionsOrString& aOptions,
                            ErrorResult& rv)
{
  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  rv = nsContentUtils::GetNodeInfoFromQName(aNamespaceURI,
                                            aQualifiedName,
                                            mNodeInfoManager,
                                            nsIDOMNode::ELEMENT_NODE,
                                            getter_AddRefs(nodeInfo));
  if (rv.Failed()) {
    return nullptr;
  }

  const nsString* is = nullptr;
  if (CustomElementRegistry::IsCustomElementEnabled() &&
      aOptions.IsElementCreationOptions()) {
    const ElementCreationOptions& options = aOptions.GetAsElementCreationOptions();
    if (options.mIs.WasPassed()) {
      is = &options.mIs.Value();
    }
  }

  nsCOMPtr<Element> element;
  rv = NS_NewElement(getter_AddRefs(element), nodeInfo.forget(),
                     NOT_FROM_PARSER, is);
  if (rv.Failed()) {
    return nullptr;
  }

  return element.forget();
}

NS_IMETHODIMP
nsDocument::CreateTextNode(const nsAString& aData, nsIDOMText** aReturn)
{
  *aReturn = nsIDocument::CreateTextNode(aData).take();
  return NS_OK;
}

already_AddRefed<nsTextNode>
nsIDocument::CreateEmptyTextNode() const
{
  RefPtr<nsTextNode> text = new nsTextNode(mNodeInfoManager);
  return text.forget();
}

already_AddRefed<nsTextNode>
nsIDocument::CreateTextNode(const nsAString& aData) const
{
  RefPtr<nsTextNode> text = new nsTextNode(mNodeInfoManager);
  // Don't notify; this node is still being created.
  text->SetText(aData, false);
  return text.forget();
}

NS_IMETHODIMP
nsDocument::CreateDocumentFragment(nsIDOMDocumentFragment** aReturn)
{
  *aReturn = nsIDocument::CreateDocumentFragment().take();
  return NS_OK;
}

already_AddRefed<DocumentFragment>
nsIDocument::CreateDocumentFragment() const
{
  RefPtr<DocumentFragment> frag = new DocumentFragment(mNodeInfoManager);
  return frag.forget();
}

NS_IMETHODIMP
nsDocument::CreateComment(const nsAString& aData, nsIDOMComment** aReturn)
{
  *aReturn = nsIDocument::CreateComment(aData).take();
  return NS_OK;
}

// Unfortunately, bareword "Comment" is ambiguous with some Mac system headers.
already_AddRefed<dom::Comment>
nsIDocument::CreateComment(const nsAString& aData) const
{
  RefPtr<dom::Comment> comment = new dom::Comment(mNodeInfoManager);

  // Don't notify; this node is still being created.
  comment->SetText(aData, false);
  return comment.forget();
}

NS_IMETHODIMP
nsDocument::CreateCDATASection(const nsAString& aData,
                               nsIDOMCDATASection** aReturn)
{
  NS_ENSURE_ARG_POINTER(aReturn);
  ErrorResult rv;
  *aReturn = nsIDocument::CreateCDATASection(aData, rv).take();
  return rv.StealNSResult();
}

already_AddRefed<CDATASection>
nsIDocument::CreateCDATASection(const nsAString& aData,
                                ErrorResult& rv)
{
  if (IsHTMLDocument()) {
    rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return nullptr;
  }

  if (FindInReadable(NS_LITERAL_STRING("]]>"), aData)) {
    rv.Throw(NS_ERROR_DOM_INVALID_CHARACTER_ERR);
    return nullptr;
  }

  RefPtr<CDATASection> cdata = new CDATASection(mNodeInfoManager);

  // Don't notify; this node is still being created.
  cdata->SetText(aData, false);

  return cdata.forget();
}

NS_IMETHODIMP
nsDocument::CreateProcessingInstruction(const nsAString& aTarget,
                                        const nsAString& aData,
                                        nsIDOMProcessingInstruction** aReturn)
{
  ErrorResult rv;
  *aReturn =
    nsIDocument::CreateProcessingInstruction(aTarget, aData, rv).take();
  return rv.StealNSResult();
}

already_AddRefed<ProcessingInstruction>
nsIDocument::CreateProcessingInstruction(const nsAString& aTarget,
                                         const nsAString& aData,
                                         ErrorResult& rv) const
{
  nsresult res = nsContentUtils::CheckQName(aTarget, false);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  if (FindInReadable(NS_LITERAL_STRING("?>"), aData)) {
    rv.Throw(NS_ERROR_DOM_INVALID_CHARACTER_ERR);
    return nullptr;
  }

  RefPtr<ProcessingInstruction> pi =
    NS_NewXMLProcessingInstruction(mNodeInfoManager, aTarget, aData);

  return pi.forget();
}

NS_IMETHODIMP
nsDocument::CreateAttribute(const nsAString& aName,
                            nsIDOMAttr** aReturn)
{
  ErrorResult rv;
  *aReturn = nsIDocument::CreateAttribute(aName, rv).take();
  return rv.StealNSResult();
}

already_AddRefed<Attr>
nsIDocument::CreateAttribute(const nsAString& aName, ErrorResult& rv)
{
  WarnOnceAbout(eCreateAttribute);

  if (!mNodeInfoManager) {
    rv.Throw(NS_ERROR_NOT_INITIALIZED);
    return nullptr;
  }

  nsresult res = nsContentUtils::CheckQName(aName, false);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  nsAutoString name;
  if (IsHTMLDocument()) {
    nsContentUtils::ASCIIToLower(aName, name);
  } else {
    name = aName;
  }

  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  res = mNodeInfoManager->GetNodeInfo(name, nullptr, kNameSpaceID_None,
                                      nsIDOMNode::ATTRIBUTE_NODE,
                                      getter_AddRefs(nodeInfo));
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  RefPtr<Attr> attribute = new Attr(nullptr, nodeInfo.forget(),
                                    EmptyString());
  return attribute.forget();
}

NS_IMETHODIMP
nsDocument::CreateAttributeNS(const nsAString & aNamespaceURI,
                              const nsAString & aQualifiedName,
                              nsIDOMAttr **aResult)
{
  ErrorResult rv;
  *aResult =
    nsIDocument::CreateAttributeNS(aNamespaceURI, aQualifiedName, rv).take();
  return rv.StealNSResult();
}

already_AddRefed<Attr>
nsIDocument::CreateAttributeNS(const nsAString& aNamespaceURI,
                               const nsAString& aQualifiedName,
                               ErrorResult& rv)
{
  WarnOnceAbout(eCreateAttributeNS);

  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  rv = nsContentUtils::GetNodeInfoFromQName(aNamespaceURI,
                                            aQualifiedName,
                                            mNodeInfoManager,
                                            nsIDOMNode::ATTRIBUTE_NODE,
                                            getter_AddRefs(nodeInfo));
  if (rv.Failed()) {
    return nullptr;
  }

  RefPtr<Attr> attribute = new Attr(nullptr, nodeInfo.forget(),
                                    EmptyString());
  return attribute.forget();
}

bool
nsDocument::CustomElementConstructor(JSContext* aCx, unsigned aArgc, JS::Value* aVp)
{
  JS::CallArgs args = JS::CallArgsFromVp(aArgc, aVp);

  JS::Rooted<JSObject*> global(aCx,
    JS_GetGlobalForObject(aCx, &args.callee()));
  RefPtr<nsGlobalWindow> window;
  UNWRAP_OBJECT(Window, global, window);
  MOZ_ASSERT(window, "Should have a non-null window");

  nsDocument* document = static_cast<nsDocument*>(window->GetDoc());

  // Function name is the type of the custom element.
  JSString* jsFunName =
    JS_GetFunctionId(JS_ValueToFunction(aCx, args.calleev()));
  nsAutoJSString elemName;
  if (!elemName.init(aCx, jsFunName)) {
    return true;
  }

  RefPtr<mozilla::dom::CustomElementRegistry> registry = window->CustomElements();
  if (!registry) {
    return true;
  }

  nsCOMPtr<nsIAtom> typeAtom(NS_Atomize(elemName));
  CustomElementDefinition* definition = registry->mCustomDefinitions.Get(typeAtom);
  if (!definition) {
    return true;
  }

  RefPtr<Element> element;

  // We integrate with construction stack and do prototype swizzling here, so
  // that old upgrade behavior could also share the new upgrade steps.
  // And this old upgrade will be remove at some point (when everything is
  // switched to latest custom element spec).
  nsTArray<RefPtr<nsGenericHTMLElement>>& constructionStack =
    definition->mConstructionStack;
  if (constructionStack.Length()) {
    element = constructionStack.LastElement();
    NS_ENSURE_TRUE(element != ALEADY_CONSTRUCTED_MARKER, false);

    // Do prototype swizzling if dom reflector exists.
    JS::Rooted<JSObject*> reflector(aCx, element->GetWrapper());
    if (reflector) {
      Maybe<JSAutoCompartment> ac;
      JS::Rooted<JSObject*> prototype(aCx, definition->mPrototype);
      if (element->NodePrincipal()->SubsumesConsideringDomain(nsContentUtils::ObjectPrincipal(prototype))) {
        ac.emplace(aCx, reflector);
        if (!JS_WrapObject(aCx, &prototype) ||
            !JS_SetPrototype(aCx, reflector, prototype)) {
          return false;
        }
      } else {
        // We want to set the custom prototype in the compartment where it was
        // registered. We store the prototype from define() without unwrapped,
        // hence the prototype's compartment is the compartment where it was
        // registered.
        // In the case that |reflector| and |prototype| are in different
        // compartments, this will set the prototype on the |reflector|'s wrapper
        // and thus only visible in the wrapper's compartment, since we know
        // reflector's principal does not subsume prototype's in this case.
        ac.emplace(aCx, prototype);
        if (!JS_WrapObject(aCx, &reflector) ||
            !JS_SetPrototype(aCx, reflector, prototype)) {
          return false;
        }
      }

      // Wrap into current context.
      if (!JS_WrapObject(aCx, &reflector)) {
        return false;
      }

      args.rval().setObject(*reflector);
      return true;
    }
  } else {
    nsDependentAtomString localName(definition->mLocalName);
    element =
      document->CreateElem(localName, nullptr, kNameSpaceID_XHTML,
                           (definition->mLocalName != typeAtom) ? &elemName
                                                                : nullptr);
    NS_ENSURE_TRUE(element, false);
  }

  // The prototype setup happens in Element::WrapObject().
  nsresult rv = nsContentUtils::WrapNative(aCx, element, element, args.rval());
  NS_ENSURE_SUCCESS(rv, true);

  return true;
}

bool
nsDocument::IsWebComponentsEnabled(JSContext* aCx, JSObject* aObject)
{
  if (!nsContentUtils::IsWebComponentsEnabled()) {
    return false;
  }

  JS::Rooted<JSObject*> obj(aCx, aObject);

  JSAutoCompartment ac(aCx, obj);
  JS::Rooted<JSObject*> global(aCx, JS_GetGlobalForObject(aCx, obj));
  nsCOMPtr<nsPIDOMWindowInner> window =
    do_QueryInterface(nsJSUtils::GetStaticScriptGlobal(global));

  nsIDocument* doc = window ? window->GetExtantDoc() : nullptr;
  if (doc && doc->IsStyledByServo()) {
    NS_WARNING("stylo: Web Components not supported yet");
    return false;
  }

  return true;
}

bool
nsDocument::IsWebComponentsEnabled(dom::NodeInfo* aNodeInfo)
{
  if (!nsContentUtils::IsWebComponentsEnabled()) {
    return false;
  }

  nsIDocument* doc = aNodeInfo->GetDocument();
  if (doc->IsStyledByServo()) {
    NS_WARNING("stylo: Web Components not supported yet");
    return false;
  }

  return true;
}

void
nsDocument::ScheduleSVGForPresAttrEvaluation(nsSVGElement* aSVG)
{
  mLazySVGPresElements.PutEntry(aSVG);
}

void
nsDocument::UnscheduleSVGForPresAttrEvaluation(nsSVGElement* aSVG)
{
  mLazySVGPresElements.RemoveEntry(aSVG);
}

void
nsDocument::ResolveScheduledSVGPresAttrs()
{
  for (auto iter = mLazySVGPresElements.Iter(); !iter.Done(); iter.Next()) {
    nsSVGElement* svg = iter.Get()->GetKey();
    svg->UpdateContentDeclarationBlock(StyleBackendType::Servo);
  }
  mLazySVGPresElements.Clear();
}

void
nsDocument::RegisterElement(JSContext* aCx, const nsAString& aType,
                            const ElementRegistrationOptions& aOptions,
                            JS::MutableHandle<JSObject*> aRetval,
                            ErrorResult& rv)
{
  RefPtr<CustomElementRegistry> registry(GetCustomElementRegistry());
  if (!registry) {
    rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return;
  }

  AutoCEReaction ceReaction(this->GetDocGroup()->CustomElementReactionsStack());
  // Unconditionally convert TYPE to lowercase.
  nsAutoString lcType;
  nsContentUtils::ASCIIToLower(aType, lcType);

  nsIGlobalObject* sgo = GetScopeObject();
  if (!sgo) {
    rv.Throw(NS_ERROR_UNEXPECTED);
    return;
  }

  JS::Rooted<JSObject*> global(aCx, sgo->GetGlobalJSObject());
  JS::Rooted<JSObject*> protoObject(aCx);

  if (!aOptions.mPrototype) {
    JS::Rooted<JSObject*> htmlProto(aCx);
    htmlProto = HTMLElementBinding::GetProtoObjectHandle(aCx);
    if (!htmlProto) {
      rv.Throw(NS_ERROR_OUT_OF_MEMORY);
      return;
    }

    protoObject = JS_NewObjectWithGivenProto(aCx, nullptr, htmlProto);
    if (!protoObject) {
      rv.Throw(NS_ERROR_UNEXPECTED);
      return;
    }
  } else {
    protoObject = aOptions.mPrototype;

    // Get the unwrapped prototype to do some checks.
    JS::Rooted<JSObject*> protoObjectUnwrapped(aCx, js::CheckedUnwrap(protoObject));
    if (