dom/base/nsContentUtils.cpp
author Kyle Machulis <kyle@nonpolynomial.com>
Wed, 11 Apr 2018 16:18:20 -0700
changeset 467482 77694987ba61cf176fc403badc29431158f3f831
parent 466890 37b8862d354e0014a72715462dd2102dd5b599cc
child 467745 a437a5c0f2ae18cc3ed35f8d6db47f3873d0d3ec
permissions -rw-r--r--
Bug 1453517 - Consolidate popup permission checks to nsContentUtils; r=bz Permissions checks for popups were happening in nsIPopupWindowManager, but that really only required a pref and perm check. The XPCOM machinery around this isn't really needed, and the check was only called from two places in content, so this fits in nsContentUtils. MozReview-Commit-ID: 9x60x1BKWcr

/* -*- 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/. */

/* A namespace class for static layout utilities. */

#include "nsContentUtils.h"

#include <algorithm>
#include <math.h>

#include "DecoderTraits.h"
#include "harfbuzz/hb.h"
#include "imgICache.h"
#include "imgIContainer.h"
#include "imgINotificationObserver.h"
#include "imgLoader.h"
#include "imgRequestProxy.h"
#include "jsapi.h"
#include "jsfriendapi.h"
#include "js/Value.h"
#include "Layers.h"
#include "nsAppRunner.h"
// nsNPAPIPluginInstance must be included before nsIDocument.h, which is included in mozAutoDocUpdate.h.
#include "nsNPAPIPluginInstance.h"
#include "gfxDrawable.h"
#include "gfxPrefs.h"
#include "ImageOps.h"
#include "mozAutoDocUpdate.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/AutoTimelineMarker.h"
#include "mozilla/Base64.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/LoadInfo.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/CustomElementRegistry.h"
#include "mozilla/dom/DocumentFragment.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/DOMExceptionBinding.h"
#include "mozilla/dom/DOMTypes.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ElementInlines.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/FileSystemSecurity.h"
#include "mozilla/dom/FileBlobImpl.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "mozilla/dom/HTMLSlotElement.h"
#include "mozilla/dom/HTMLTemplateElement.h"
#include "mozilla/dom/IDTracker.h"
#include "mozilla/dom/MouseEventBinding.h"
#include "mozilla/dom/KeyboardEventBinding.h"
#include "mozilla/dom/IPCBlobUtils.h"
#include "mozilla/dom/NodeBinding.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/ScriptSettings.h"
#include "mozilla/dom/TabParent.h"
#include "mozilla/dom/Text.h"
#include "mozilla/dom/TouchEvent.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/XULCommandEvent.h"
#include "mozilla/dom/WorkerCommon.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/EventListenerManager.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/gfx/DataSurfaceHelpers.h"
#include "mozilla/HTMLEditor.h"
#include "mozilla/IMEStateManager.h"
#include "mozilla/InternalMutationEvent.h"
#include "mozilla/Likely.h"
#include "mozilla/ManualNAC.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/Preferences.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/dom/Selection.h"
#include "mozilla/TextEvents.h"
#include "nsArrayUtils.h"
#include "nsAString.h"
#include "nsAttrName.h"
#include "nsAttrValue.h"
#include "nsAttrValueInlines.h"
#include "nsBindingManager.h"
#include "nsCanvasFrame.h"
#include "nsCaret.h"
#include "nsCCUncollectableMarker.h"
#include "nsCharSeparatedTokenizer.h"
#include "nsCOMPtr.h"
#include "nsContentCreatorFunctions.h"
#include "nsContentDLF.h"
#include "nsContentList.h"
#include "nsContentPolicyUtils.h"
#include "nsContentSecurityManager.h"
#include "nsCPrefetchService.h"
#include "nsCRT.h"
#include "nsCycleCollectionParticipant.h"
#include "nsCycleCollector.h"
#include "nsDataHashtable.h"
#include "nsDocShellCID.h"
#include "nsDocument.h"
#include "nsDOMCID.h"
#include "mozilla/dom/DataTransfer.h"
#include "nsDOMJSUtils.h"
#include "nsDOMMutationObserver.h"
#include "nsError.h"
#include "nsFocusManager.h"
#include "nsGenericHTMLElement.h"
#include "nsGenericHTMLFrameElement.h"
#include "nsGkAtoms.h"
#include "nsHostObjectProtocolHandler.h"
#include "nsHtml5Module.h"
#include "nsHtml5StringParser.h"
#include "nsHTMLDocument.h"
#include "nsHTMLTags.h"
#include "nsIAddonPolicyService.h"
#include "nsIAnonymousContentCreator.h"
#include "nsIAsyncVerifyRedirectCallback.h"
#include "nsICategoryManager.h"
#include "nsIChannelEventSink.h"
#include "nsICharsetDetectionObserver.h"
#include "nsIChromeRegistry.h"
#include "nsIConsoleService.h"
#include "nsIContent.h"
#include "nsIContentInlines.h"
#include "nsIContentSecurityPolicy.h"
#include "nsIContentSink.h"
#include "nsIContentViewer.h"
#include "nsIDocShell.h"
#include "nsIDocShellTreeOwner.h"
#include "nsIDocument.h"
#include "nsIDocumentEncoder.h"
#include "nsIDOMChromeWindow.h"
#include "nsIDOMDocument.h"
#include "nsIDOMElement.h"
#include "nsIDOMNode.h"
#include "nsIDOMNodeList.h"
#include "nsIDOMWindowUtils.h"
#include "nsIDragService.h"
#include "nsIFormControl.h"
#include "nsIForm.h"
#include "nsIFragmentContentSink.h"
#include "nsContainerFrame.h"
#include "nsIHTMLDocument.h"
#include "nsIIdleService.h"
#include "nsIImageLoadingContent.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIIOService.h"
#include "nsILoadContext.h"
#include "nsILoadGroup.h"
#include "nsIMemoryReporter.h"
#include "nsIMIMEHeaderParam.h"
#include "nsIMIMEService.h"
#include "nsINode.h"
#include "mozilla/dom/NodeInfo.h"
#include "nsIObjectLoadingContent.h"
#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsIOfflineCacheUpdate.h"
#include "nsIParser.h"
#include "nsIParserUtils.h"
#include "nsIPermissionManager.h"
#include "nsIPluginHost.h"
#include "nsIRemoteBrowser.h"
#include "nsIRequest.h"
#include "nsIRunnable.h"
#include "nsIScriptContext.h"
#include "nsIScriptError.h"
#include "nsIScriptGlobalObject.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIScriptSecurityManager.h"
#include "nsIScrollable.h"
#include "nsIStreamConverterService.h"
#include "nsIStringBundle.h"
#include "nsIURI.h"
#include "nsIURIWithPrincipal.h"
#include "nsIURL.h"
#include "nsIWebNavigation.h"
#include "nsIWindowMediator.h"
#include "nsIXPConnect.h"
#include "nsJSUtils.h"
#include "nsMappedAttributes.h"
#include "nsNetCID.h"
#include "nsNetUtil.h"
#include "nsNodeInfoManager.h"
#include "NullPrincipal.h"
#include "nsParserCIID.h"
#include "nsParserConstants.h"
#include "nsPIDOMWindow.h"
#include "nsPresContext.h"
#include "nsPrintfCString.h"
#include "nsSandboxFlags.h"
#include "nsScriptSecurityManager.h"
#include "nsSerializationHelper.h"
#include "nsStreamUtils.h"
#include "nsTextEditorState.h"
#include "nsTextFragment.h"
#include "nsTextNode.h"
#include "nsThreadUtils.h"
#include "nsTreeSanitizer.h"
#include "nsUnicodeProperties.h"
#include "nsURLHelper.h"
#include "nsViewManager.h"
#include "nsViewportInfo.h"
#include "nsWidgetsCID.h"
#include "nsIWindowProvider.h"
#include "nsWrapperCacheInlines.h"
#include "nsXULPopupManager.h"
#include "xpcprivate.h" // nsXPConnect
#include "HTMLSplitOnSpacesTokenizer.h"
#include "nsContentTypeParser.h"
#include "nsICookiePermission.h"
#include "mozIThirdPartyUtil.h"
#include "nsICookieService.h"
#include "mozilla/EnumSet.h"
#include "mozilla/BloomFilter.h"
#include "TabChild.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/TabGroup.h"
#include "nsIWebNavigationInfo.h"
#include "nsPluginHost.h"
#include "mozilla/HangAnnotations.h"
#include "mozilla/Encoding.h"
#include "nsXULElement.h"

#include "nsIBidiKeyboard.h"

#if defined(XP_WIN)
// Undefine LoadImage to prevent naming conflict with Windows.
#undef LoadImage
#endif

extern "C" int MOZ_XMLTranslateEntity(const char* ptr, const char* end,
                                      const char** next, char16_t* result);
extern "C" int MOZ_XMLCheckQName(const char* ptr, const char* end,
                                 int ns_aware, const char** colon);

class imgLoader;
class nsAtom;

using namespace mozilla::dom;
using namespace mozilla::ipc;
using namespace mozilla::gfx;
using namespace mozilla::layers;
using namespace mozilla::widget;
using namespace mozilla;

const char kLoadAsData[] = "loadAsData";

nsIXPConnect *nsContentUtils::sXPConnect;
nsIScriptSecurityManager *nsContentUtils::sSecurityManager;
nsIPrincipal *nsContentUtils::sSystemPrincipal;
nsIPrincipal *nsContentUtils::sNullSubjectPrincipal;
nsNameSpaceManager *nsContentUtils::sNameSpaceManager;
nsIIOService *nsContentUtils::sIOService;
nsIUUIDGenerator *nsContentUtils::sUUIDGenerator;
nsIConsoleService *nsContentUtils::sConsoleService;
nsDataHashtable<nsRefPtrHashKey<nsAtom>, EventNameMapping>* nsContentUtils::sAtomEventTable = nullptr;
nsDataHashtable<nsStringHashKey, EventNameMapping>* nsContentUtils::sStringEventTable = nullptr;
nsTArray<RefPtr<nsAtom>>* nsContentUtils::sUserDefinedEvents = nullptr;
nsIStringBundleService *nsContentUtils::sStringBundleService;
nsIStringBundle *nsContentUtils::sStringBundles[PropertiesFile_COUNT];
nsIContentPolicy *nsContentUtils::sContentPolicyService;
bool nsContentUtils::sTriedToGetContentPolicy = false;
RefPtr<mozilla::intl::LineBreaker> nsContentUtils::sLineBreaker;
RefPtr<mozilla::intl::WordBreaker> nsContentUtils::sWordBreaker;
nsIBidiKeyboard *nsContentUtils::sBidiKeyboard = nullptr;
uint32_t nsContentUtils::sScriptBlockerCount = 0;
uint32_t nsContentUtils::sDOMNodeRemovedSuppressCount = 0;
AutoTArray<nsCOMPtr<nsIRunnable>, 8>* nsContentUtils::sBlockedScriptRunners = nullptr;
uint32_t nsContentUtils::sRunnersCountAtFirstBlocker = 0;
nsIInterfaceRequestor* nsContentUtils::sSameOriginChecker = nullptr;

bool nsContentUtils::sIsHandlingKeyBoardEvent = false;
bool nsContentUtils::sAllowXULXBL_for_file = false;
bool nsContentUtils::sDisablePopups = false;

nsString* nsContentUtils::sShiftText = nullptr;
nsString* nsContentUtils::sControlText = nullptr;
nsString* nsContentUtils::sMetaText = nullptr;
nsString* nsContentUtils::sOSText = nullptr;
nsString* nsContentUtils::sAltText = nullptr;
nsString* nsContentUtils::sModifierSeparator = nullptr;

bool nsContentUtils::sInitialized = false;
bool nsContentUtils::sIsFullScreenApiEnabled = false;
bool nsContentUtils::sIsUnprefixedFullscreenApiEnabled = false;
bool nsContentUtils::sTrustedFullScreenOnly = true;
bool nsContentUtils::sIsCutCopyAllowed = true;
bool nsContentUtils::sIsUpgradableDisplayContentPrefEnabled = false;
bool nsContentUtils::sIsFrameTimingPrefEnabled = false;
bool nsContentUtils::sIsPerformanceTimingEnabled = false;
bool nsContentUtils::sIsResourceTimingEnabled = false;
bool nsContentUtils::sIsPerformanceNavigationTimingEnabled = false;
bool nsContentUtils::sIsFormAutofillAutocompleteEnabled = false;
bool nsContentUtils::sIsShadowDOMEnabled = false;
bool nsContentUtils::sIsCustomElementsEnabled = false;
bool nsContentUtils::sSendPerformanceTimingNotifications = false;
bool nsContentUtils::sUseActivityCursor = false;
bool nsContentUtils::sAnimationsAPICoreEnabled = false;
bool nsContentUtils::sAnimationsAPIElementAnimateEnabled = false;
bool nsContentUtils::sGetBoxQuadsEnabled = false;
bool nsContentUtils::sSkipCursorMoveForSameValueSet = false;
bool nsContentUtils::sRequestIdleCallbackEnabled = false;
bool nsContentUtils::sLowerNetworkPriority = false;
bool nsContentUtils::sTailingEnabled = false;
bool nsContentUtils::sShowInputPlaceholderOnFocus = true;
bool nsContentUtils::sAutoFocusEnabled = true;
#ifndef RELEASE_OR_BETA
bool nsContentUtils::sBypassCSSOMOriginCheck = false;
#endif

bool nsContentUtils::sIsBytecodeCacheEnabled = false;
int32_t nsContentUtils::sBytecodeCacheStrategy = 0;
nsCString* nsContentUtils::sJSBytecodeMimeType = nullptr;

int32_t nsContentUtils::sPrivacyMaxInnerWidth = 1000;
int32_t nsContentUtils::sPrivacyMaxInnerHeight = 1000;

nsContentUtils::UserInteractionObserver*
nsContentUtils::sUserInteractionObserver = nullptr;

uint32_t nsContentUtils::sHandlingInputTimeout = 1000;

uint32_t nsContentUtils::sCookiesLifetimePolicy = nsICookieService::ACCEPT_NORMALLY;
uint32_t nsContentUtils::sCookiesBehavior = nsICookieService::BEHAVIOR_ACCEPT;

nsHtml5StringParser* nsContentUtils::sHTMLFragmentParser = nullptr;
nsIParser* nsContentUtils::sXMLFragmentParser = nullptr;
nsIFragmentContentSink* nsContentUtils::sXMLFragmentSink = nullptr;
bool nsContentUtils::sFragmentParsingActive = false;

bool nsContentUtils::sDoNotTrackEnabled = false;

mozilla::LazyLogModule nsContentUtils::sDOMDumpLog("Dump");

PopupControlState nsContentUtils::sPopupControlState = openAbused;

int32_t nsContentUtils::sInnerOrOuterWindowCount = 0;
uint32_t nsContentUtils::sInnerOrOuterWindowSerialCounter = 0;

// Subset of http://www.whatwg.org/specs/web-apps/current-work/#autofill-field-name
enum AutocompleteUnsupportedFieldName : uint8_t
{
  #define AUTOCOMPLETE_UNSUPPORTED_FIELD_NAME(name_, value_) \
    eAutocompleteUnsupportedFieldName_##name_,
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_UNSUPPORTED_FIELD_NAME
};

enum AutocompleteUnsupportFieldContactHint : uint8_t
{
  #define AUTOCOMPLETE_UNSUPPORTED_FIELD_CONTACT_HINT(name_, value_) \
    eAutocompleteUnsupportedFieldContactHint_##name_,
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_UNSUPPORTED_FIELD_CONTACT_HINT
};

enum AutocompleteFieldName : uint8_t
{
  #define AUTOCOMPLETE_FIELD_NAME(name_, value_) \
    eAutocompleteFieldName_##name_,
  #define AUTOCOMPLETE_CONTACT_FIELD_NAME(name_, value_) \
    AUTOCOMPLETE_FIELD_NAME(name_, value_)
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_NAME
  #undef AUTOCOMPLETE_CONTACT_FIELD_NAME
};

enum AutocompleteFieldHint : uint8_t
{
  #define AUTOCOMPLETE_FIELD_HINT(name_, value_) \
    eAutocompleteFieldHint_##name_,
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_HINT
};

enum AutocompleteFieldContactHint : uint8_t
{
  #define AUTOCOMPLETE_FIELD_CONTACT_HINT(name_, value_) \
    eAutocompleteFieldContactHint_##name_,
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_CONTACT_HINT
};

enum AutocompleteCategory
{
  #define AUTOCOMPLETE_CATEGORY(name_, value_) eAutocompleteCategory_##name_,
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_CATEGORY
};

static const nsAttrValue::EnumTable kAutocompleteUnsupportedFieldNameTable[] = {
  #define AUTOCOMPLETE_UNSUPPORTED_FIELD_NAME(name_, value_) \
    { value_, eAutocompleteUnsupportedFieldName_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_UNSUPPORTED_FIELD_NAME
  { nullptr, 0 }
};

static const nsAttrValue::EnumTable kAutocompleteUnsupportedContactFieldHintTable[] = {
  #define AUTOCOMPLETE_UNSUPPORTED_FIELD_CONTACT_HINT(name_, value_) \
    { value_, eAutocompleteUnsupportedFieldContactHint_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_UNSUPPORTED_FIELD_CONTACT_HINT
  { nullptr, 0 }
};


static const nsAttrValue::EnumTable kAutocompleteFieldNameTable[] = {
  #define AUTOCOMPLETE_FIELD_NAME(name_, value_) \
    { value_, eAutocompleteFieldName_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_NAME
  { nullptr, 0 }
};

static const nsAttrValue::EnumTable kAutocompleteContactFieldNameTable[] = {
  #define AUTOCOMPLETE_CONTACT_FIELD_NAME(name_, value_) \
    { value_, eAutocompleteFieldName_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_CONTACT_FIELD_NAME
  { nullptr, 0 }
};

static const nsAttrValue::EnumTable kAutocompleteFieldHintTable[] = {
  #define AUTOCOMPLETE_FIELD_HINT(name_, value_) \
    { value_, eAutocompleteFieldHint_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_HINT
  { nullptr, 0 }
};

static const nsAttrValue::EnumTable kAutocompleteContactFieldHintTable[] = {
  #define AUTOCOMPLETE_FIELD_CONTACT_HINT(name_, value_) \
    { value_, eAutocompleteFieldContactHint_##name_ },
  #include "AutocompleteFieldList.h"
  #undef AUTOCOMPLETE_FIELD_CONTACT_HINT
  { nullptr, 0 }
};

namespace {

static NS_DEFINE_CID(kCParserCID, NS_PARSER_CID);

static PLDHashTable* sEventListenerManagersHash;

class DOMEventListenerManagersHashReporter final : public nsIMemoryReporter
{
  MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf)

  ~DOMEventListenerManagersHashReporter() = default;

public:
  NS_DECL_ISUPPORTS

  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                            nsISupports* aData, bool aAnonymize) override
  {
    // We don't measure the |EventListenerManager| objects pointed to by the
    // entries because those references are non-owning.
    int64_t amount = sEventListenerManagersHash
                   ? sEventListenerManagersHash->ShallowSizeOfIncludingThis(
                       MallocSizeOf)
                   : 0;

    MOZ_COLLECT_REPORT(
      "explicit/dom/event-listener-managers-hash", KIND_HEAP, UNITS_BYTES,
      amount,
      "Memory used by the event listener manager's hash table.");

    return NS_OK;
  }
};

NS_IMPL_ISUPPORTS(DOMEventListenerManagersHashReporter, nsIMemoryReporter)

class EventListenerManagerMapEntry : public PLDHashEntryHdr
{
public:
  explicit EventListenerManagerMapEntry(const void* aKey)
    : mKey(aKey)
  {
  }

  ~EventListenerManagerMapEntry()
  {
    NS_ASSERTION(!mListenerManager, "caller must release and disconnect ELM");
  }

protected:          // declared protected to silence clang warnings
  const void *mKey; // must be first, to look like PLDHashEntryStub

public:
  RefPtr<EventListenerManager> mListenerManager;
};

static void
EventListenerManagerHashInitEntry(PLDHashEntryHdr *entry, const void *key)
{
  // Initialize the entry with placement new
  new (entry) EventListenerManagerMapEntry(key);
}

static void
EventListenerManagerHashClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry)
{
  EventListenerManagerMapEntry *lm =
    static_cast<EventListenerManagerMapEntry *>(entry);

  // Let the EventListenerManagerMapEntry clean itself up...
  lm->~EventListenerManagerMapEntry();
}

class SameOriginCheckerImpl final : public nsIChannelEventSink,
                                    public nsIInterfaceRequestor
{
  ~SameOriginCheckerImpl() = default;

  NS_DECL_ISUPPORTS
  NS_DECL_NSICHANNELEVENTSINK
  NS_DECL_NSIINTERFACEREQUESTOR
};

} // namespace

/**
 * This class is used to determine whether or not the user is currently
 * interacting with the browser. It listens to observer events to toggle the
 * value of the sUserActive static.
 *
 * This class is an internal implementation detail.
 * nsContentUtils::GetUserIsInteracting() should be used to access current
 * user interaction status.
 */
class nsContentUtils::UserInteractionObserver final : public nsIObserver
                                                    , public HangMonitor::Annotator
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIOBSERVER

  void Init();
  void Shutdown();
  void AnnotateHang(HangMonitor::HangAnnotations& aAnnotations) override;

  static Atomic<bool> sUserActive;

private:
  ~UserInteractionObserver() {}
};

/* static */
TimeDuration
nsContentUtils::HandlingUserInputTimeout()
{
  return TimeDuration::FromMilliseconds(sHandlingInputTimeout);
}

// static
nsresult
nsContentUtils::Init()
{
  if (sInitialized) {
    NS_WARNING("Init() called twice");

    return NS_OK;
  }

  nsHTMLTags::AddRefTable();

  sNameSpaceManager = nsNameSpaceManager::GetInstance();
  NS_ENSURE_TRUE(sNameSpaceManager, NS_ERROR_OUT_OF_MEMORY);

  sXPConnect = nsXPConnect::XPConnect();
  // We hold a strong ref to sXPConnect to ensure that it does not go away until
  // nsLayoutStatics::Shutdown is happening.  Otherwise ~nsXPConnect can be
  // triggered by xpcModuleDtor late in shutdown and cause crashes due to
  // various stuff already being torn down by then.  Note that this means that
  // we are effectively making sure that if we leak nsLayoutStatics then we also
  // leak nsXPConnect.
  NS_ADDREF(sXPConnect);

  sSecurityManager = nsScriptSecurityManager::GetScriptSecurityManager();
  if(!sSecurityManager)
    return NS_ERROR_FAILURE;
  NS_ADDREF(sSecurityManager);

  sSecurityManager->GetSystemPrincipal(&sSystemPrincipal);
  MOZ_ASSERT(sSystemPrincipal);

  RefPtr<NullPrincipal> nullPrincipal = NullPrincipal::CreateWithoutOriginAttributes();
  if (!nullPrincipal) {
    return NS_ERROR_FAILURE;
  }

  nullPrincipal.forget(&sNullSubjectPrincipal);

  nsresult rv = CallGetService(NS_IOSERVICE_CONTRACTID, &sIOService);
  if (NS_FAILED(rv)) {
    // This makes life easier, but we can live without it.

    sIOService = nullptr;
  }

  sLineBreaker = mozilla::intl::LineBreaker::Create();

  sWordBreaker = mozilla::intl::WordBreaker::Create();

  if (!InitializeEventTable())
    return NS_ERROR_FAILURE;

  if (!sEventListenerManagersHash) {
    static const PLDHashTableOps hash_table_ops =
    {
      PLDHashTable::HashVoidPtrKeyStub,
      PLDHashTable::MatchEntryStub,
      PLDHashTable::MoveEntryStub,
      EventListenerManagerHashClearEntry,
      EventListenerManagerHashInitEntry
    };

    sEventListenerManagersHash =
      new PLDHashTable(&hash_table_ops, sizeof(EventListenerManagerMapEntry));

    RegisterStrongMemoryReporter(new DOMEventListenerManagersHashReporter());
  }

  sBlockedScriptRunners = new AutoTArray<nsCOMPtr<nsIRunnable>, 8>;

  Preferences::AddBoolVarCache(&sAllowXULXBL_for_file,
                               "dom.allow_XUL_XBL_for_file");

  Preferences::AddBoolVarCache(&sIsFullScreenApiEnabled,
                               "full-screen-api.enabled");

  Preferences::AddBoolVarCache(&sIsUnprefixedFullscreenApiEnabled,
                               "full-screen-api.unprefix.enabled");

  Preferences::AddBoolVarCache(&sTrustedFullScreenOnly,
                               "full-screen-api.allow-trusted-requests-only");

  Preferences::AddBoolVarCache(&sIsCutCopyAllowed,
                               "dom.allow_cut_copy", true);

  Preferences::AddBoolVarCache(&sIsPerformanceTimingEnabled,
                               "dom.enable_performance", true);

  Preferences::AddBoolVarCache(&sIsResourceTimingEnabled,
                               "dom.enable_resource_timing", true);

  Preferences::AddBoolVarCache(&sIsPerformanceNavigationTimingEnabled,
                               "dom.enable_performance_navigation_timing", true);

  Preferences::AddBoolVarCache(&sIsUpgradableDisplayContentPrefEnabled,
                               "security.mixed_content.upgrade_display_content", false);

  Preferences::AddBoolVarCache(&sIsFrameTimingPrefEnabled,
                               "dom.enable_frame_timing", false);

  Preferences::AddBoolVarCache(&sIsFormAutofillAutocompleteEnabled,
                               "dom.forms.autocomplete.formautofill", false);

  Preferences::AddBoolVarCache(&sIsShadowDOMEnabled,
                               "dom.webcomponents.shadowdom.enabled", false);

  Preferences::AddBoolVarCache(&sIsCustomElementsEnabled,
                               "dom.webcomponents.customelements.enabled", false);

  Preferences::AddIntVarCache(&sPrivacyMaxInnerWidth,
                              "privacy.window.maxInnerWidth",
                              1000);

  Preferences::AddIntVarCache(&sPrivacyMaxInnerHeight,
                              "privacy.window.maxInnerHeight",
                              1000);

  Preferences::AddUintVarCache(&sHandlingInputTimeout,
                               "dom.event.handling-user-input-time-limit",
                               1000);

  Preferences::AddBoolVarCache(&sSendPerformanceTimingNotifications,
                               "dom.performance.enable_notify_performance_timing", false);

  Preferences::AddUintVarCache(&sCookiesLifetimePolicy,
                               "network.cookie.lifetimePolicy",
                               nsICookieService::ACCEPT_NORMALLY);

  Preferences::AddUintVarCache(&sCookiesBehavior,
                               "network.cookie.cookieBehavior",
                               nsICookieService::BEHAVIOR_ACCEPT);

  Preferences::AddBoolVarCache(&sDoNotTrackEnabled,
                               "privacy.donottrackheader.enabled", false);

  Preferences::AddBoolVarCache(&sUseActivityCursor,
                               "ui.use_activity_cursor", false);

  Preferences::AddBoolVarCache(&sAnimationsAPICoreEnabled,
                               "dom.animations-api.core.enabled", false);

  Preferences::AddBoolVarCache(&sAnimationsAPIElementAnimateEnabled,
                               "dom.animations-api.element-animate.enabled", false);

  Preferences::AddBoolVarCache(&sGetBoxQuadsEnabled,
                               "layout.css.getBoxQuads.enabled", false);

  Preferences::AddBoolVarCache(&sSkipCursorMoveForSameValueSet,
                               "dom.input.skip_cursor_move_for_same_value_set",
                               true);

  Preferences::AddBoolVarCache(&sRequestIdleCallbackEnabled,
                               "dom.requestIdleCallback.enabled", false);

#ifndef RELEASE_OR_BETA
  sBypassCSSOMOriginCheck = getenv("MOZ_BYPASS_CSSOM_ORIGIN_CHECK");
#endif

  Preferences::AddBoolVarCache(&sLowerNetworkPriority,
                               "privacy.trackingprotection.lower_network_priority", false);

  Preferences::AddBoolVarCache(&sTailingEnabled,
                               "network.http.tailing.enabled", true);

  Preferences::AddBoolVarCache(&sShowInputPlaceholderOnFocus,
                               "dom.placeholder.show_on_focus", true);

  Preferences::AddBoolVarCache(&sAutoFocusEnabled,
                               "browser.autofocus", true);

  Preferences::AddBoolVarCache(&sIsBytecodeCacheEnabled,
                               "dom.script_loader.bytecode_cache.enabled", false);

  Preferences::AddBoolVarCache(&sDisablePopups,
                               "dom.disable_open_during_load", false);

  Preferences::AddIntVarCache(&sBytecodeCacheStrategy,
                              "dom.script_loader.bytecode_cache.strategy", 0);

  nsDependentCString buildID(mozilla::PlatformBuildID());
  sJSBytecodeMimeType = new nsCString(NS_LITERAL_CSTRING("javascript/moz-bytecode-") + buildID);

  Element::InitCCCallbacks();

  Unused << nsRFPService::GetOrCreate();

  nsCOMPtr<nsIUUIDGenerator> uuidGenerator =
    do_GetService("@mozilla.org/uuid-generator;1", &rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  uuidGenerator.forget(&sUUIDGenerator);

  if (XRE_IsParentProcess()) {
    AsyncPrecreateStringBundles();
  }

  RefPtr<UserInteractionObserver> uio = new UserInteractionObserver();
  uio->Init();
  uio.forget(&sUserInteractionObserver);

  sInitialized = true;

  return NS_OK;
}

nsresult nsContentUtils::RemoveWyciwygScheme(nsIURI* aURI, nsIURI** aReturn)
{
#ifdef DEBUG
  bool isWyciwyg = false;
  aURI->SchemeIs("wyciwyg", &isWyciwyg);
  NS_PRECONDITION(isWyciwyg, "Scheme should be wyciwyg");
#endif
  nsAutoCString path;
  nsresult rv = aURI->GetPathQueryRef(path);
  NS_ENSURE_SUCCESS(rv, rv);

  uint32_t pathLength = path.Length();
  if (pathLength <= 2) {
    return NS_ERROR_FAILURE;
  }

  // Path is of the form "//123/http://foo/bar", with a variable number of
  // digits. To figure out where the "real" URL starts, search path for a '/',
  // starting at the third character.
  int32_t slashIndex = path.FindChar('/', 2);
  if (slashIndex == kNotFound) {
    return NS_ERROR_FAILURE;
  }

  return NS_NewURI(aReturn,
    Substring(path, slashIndex + 1, pathLength - slashIndex - 1));
}

void
nsContentUtils::GetShiftText(nsAString& text)
{
  if (!sShiftText)
    InitializeModifierStrings();
  text.Assign(*sShiftText);
}

void
nsContentUtils::GetControlText(nsAString& text)
{
  if (!sControlText)
    InitializeModifierStrings();
  text.Assign(*sControlText);
}

void
nsContentUtils::GetMetaText(nsAString& text)
{
  if (!sMetaText)
    InitializeModifierStrings();
  text.Assign(*sMetaText);
}

void
nsContentUtils::GetOSText(nsAString& text)
{
  if (!sOSText) {
    InitializeModifierStrings();
  }
  text.Assign(*sOSText);
}

void
nsContentUtils::GetAltText(nsAString& text)
{
  if (!sAltText)
    InitializeModifierStrings();
  text.Assign(*sAltText);
}

void
nsContentUtils::GetModifierSeparatorText(nsAString& text)
{
  if (!sModifierSeparator)
    InitializeModifierStrings();
  text.Assign(*sModifierSeparator);
}

void
nsContentUtils::InitializeModifierStrings()
{
  //load the display strings for the keyboard accelerators
  nsCOMPtr<nsIStringBundleService> bundleService =
    mozilla::services::GetStringBundleService();
  nsCOMPtr<nsIStringBundle> bundle;
  DebugOnly<nsresult> rv = NS_OK;
  if (bundleService) {
    rv = bundleService->CreateBundle( "chrome://global-platform/locale/platformKeys.properties",
                                      getter_AddRefs(bundle));
  }

  NS_ASSERTION(NS_SUCCEEDED(rv) && bundle, "chrome://global/locale/platformKeys.properties could not be loaded");
  nsAutoString shiftModifier;
  nsAutoString metaModifier;
  nsAutoString osModifier;
  nsAutoString altModifier;
  nsAutoString controlModifier;
  nsAutoString modifierSeparator;
  if (bundle) {
    //macs use symbols for each modifier key, so fetch each from the bundle, which also covers i18n
    bundle->GetStringFromName("VK_SHIFT", shiftModifier);
    bundle->GetStringFromName("VK_META", metaModifier);
    bundle->GetStringFromName("VK_WIN", osModifier);
    bundle->GetStringFromName("VK_ALT", altModifier);
    bundle->GetStringFromName("VK_CONTROL", controlModifier);
    bundle->GetStringFromName("MODIFIER_SEPARATOR", modifierSeparator);
  }
  //if any of these don't exist, we get  an empty string
  sShiftText = new nsString(shiftModifier);
  sMetaText = new nsString(metaModifier);
  sOSText = new nsString(osModifier);
  sAltText = new nsString(altModifier);
  sControlText = new nsString(controlModifier);
  sModifierSeparator = new nsString(modifierSeparator);
}

mozilla::EventClassID
nsContentUtils::GetEventClassIDFromMessage(EventMessage aEventMessage)
{
  switch (aEventMessage) {
#define MESSAGE_TO_EVENT(name_, message_, type_, struct_) \
  case message_: return struct_;
#include "mozilla/EventNameList.h"
#undef MESSAGE_TO_EVENT
  default:
    MOZ_ASSERT_UNREACHABLE("Invalid event message?");
    return eBasicEventClass;
  }
}

static nsAtom*
GetEventTypeFromMessage(EventMessage aEventMessage)
{
  switch (aEventMessage) {
#define MESSAGE_TO_EVENT(name_, message_, type_, struct_) \
  case message_: return nsGkAtoms::on##name_;
#include "mozilla/EventNameList.h"
#undef MESSAGE_TO_EVENT
  default:
    return nullptr;
  }
}

// Because of SVG/SMIL we have several atoms mapped to the same
// id, but we can rely on MESSAGE_TO_EVENT to map id to only one atom.
static bool
ShouldAddEventToStringEventTable(const EventNameMapping& aMapping)
{
  MOZ_ASSERT(aMapping.mAtom);
  return GetEventTypeFromMessage(aMapping.mMessage) == aMapping.mAtom;
}

bool
nsContentUtils::InitializeEventTable() {
  NS_ASSERTION(!sAtomEventTable, "EventTable already initialized!");
  NS_ASSERTION(!sStringEventTable, "EventTable already initialized!");

  static const EventNameMapping eventArray[] = {
#define EVENT(name_,  _message, _type, _class)          \
    { nsGkAtoms::on##name_, _type, _message, _class, false },
#define WINDOW_ONLY_EVENT EVENT
#define DOCUMENT_ONLY_EVENT EVENT
#define NON_IDL_EVENT EVENT
#include "mozilla/EventNameList.h"
#undef WINDOW_ONLY_EVENT
#undef NON_IDL_EVENT
#undef EVENT
    { nullptr }
  };

  sAtomEventTable = new nsDataHashtable<nsRefPtrHashKey<nsAtom>, EventNameMapping>(
      ArrayLength(eventArray));
  sStringEventTable = new nsDataHashtable<nsStringHashKey, EventNameMapping>(
      ArrayLength(eventArray));
  sUserDefinedEvents = new nsTArray<RefPtr<nsAtom>>(64);

  // Subtract one from the length because of the trailing null
  for (uint32_t i = 0; i < ArrayLength(eventArray) - 1; ++i) {
    MOZ_ASSERT(!sAtomEventTable->Lookup(eventArray[i].mAtom),
               "Double-defining event name; fix your EventNameList.h");
    sAtomEventTable->Put(eventArray[i].mAtom, eventArray[i]);
    if (ShouldAddEventToStringEventTable(eventArray[i])) {
      sStringEventTable->Put(
        Substring(nsDependentAtomString(eventArray[i].mAtom), 2),
        eventArray[i]);
    }
  }

  return true;
}

void
nsContentUtils::InitializeTouchEventTable()
{
  static bool sEventTableInitialized = false;
  if (!sEventTableInitialized && sAtomEventTable && sStringEventTable) {
    sEventTableInitialized = true;
    static const EventNameMapping touchEventArray[] = {
#define EVENT(name_,  _message, _type, _class)
#define TOUCH_EVENT(name_,  _message, _type, _class)      \
      { nsGkAtoms::on##name_, _type, _message, _class },
#include "mozilla/EventNameList.h"
#undef TOUCH_EVENT
#undef EVENT
      { nullptr }
    };
    // Subtract one from the length because of the trailing null
    for (uint32_t i = 0; i < ArrayLength(touchEventArray) - 1; ++i) {
      sAtomEventTable->Put(touchEventArray[i].mAtom, touchEventArray[i]);
      sStringEventTable->Put(Substring(nsDependentAtomString(touchEventArray[i].mAtom), 2),
                             touchEventArray[i]);
    }
  }
}

static bool
Is8bit(const nsAString& aString)
{
  static const char16_t EIGHT_BIT = char16_t(~0x00FF);

  for (nsAString::const_char_iterator start = aString.BeginReading(),
         end = aString.EndReading();
       start != end;
       ++start) {
    if (*start & EIGHT_BIT) {
      return false;
    }
  }

  return true;
}

nsresult
nsContentUtils::Btoa(const nsAString& aBinaryData,
                     nsAString& aAsciiBase64String)
{
  if (!Is8bit(aBinaryData)) {
    aAsciiBase64String.Truncate();
    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
  }

  return Base64Encode(aBinaryData, aAsciiBase64String);
}

nsresult
nsContentUtils::Atob(const nsAString& aAsciiBase64String,
                     nsAString& aBinaryData)
{
  if (!Is8bit(aAsciiBase64String)) {
    aBinaryData.Truncate();
    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
  }

  const char16_t* start = aAsciiBase64String.BeginReading();
  const char16_t* cur = start;
  const char16_t* end = aAsciiBase64String.EndReading();
  bool hasWhitespace = false;

  while (cur < end) {
    if (nsContentUtils::IsHTMLWhitespace(*cur)) {
      hasWhitespace = true;
      break;
    }
    cur++;
  }

  nsresult rv;

  if (hasWhitespace) {
    nsString trimmedString;

    if (!trimmedString.SetCapacity(aAsciiBase64String.Length(), fallible)) {
      return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
    }

    trimmedString.Append(start, cur - start);

    while (cur < end) {
      if (!nsContentUtils::IsHTMLWhitespace(*cur)) {
        trimmedString.Append(*cur);
      }
      cur++;
    }
    rv = Base64Decode(trimmedString, aBinaryData);
  } else {
    rv = Base64Decode(aAsciiBase64String, aBinaryData);
  }

  if (NS_FAILED(rv) && rv == NS_ERROR_INVALID_ARG) {
    return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
  }
  return rv;
}

bool
nsContentUtils::IsAutocompleteEnabled(mozilla::dom::HTMLInputElement* aInput)
{
  NS_PRECONDITION(aInput, "aInput should not be null!");

  nsAutoString autocomplete;
  aInput->GetAutocomplete(autocomplete);

  if (autocomplete.IsEmpty()) {
    auto* form = aInput->GetForm();
    if (!form) {
      return true;
    }

    form->GetAutocomplete(autocomplete);
  }

  return !autocomplete.EqualsLiteral("off");
}

nsContentUtils::AutocompleteAttrState
nsContentUtils::SerializeAutocompleteAttribute(const nsAttrValue* aAttr,
                                               nsAString& aResult,
                                               AutocompleteAttrState aCachedState)
{
  if (!aAttr ||
      aCachedState == nsContentUtils::eAutocompleteAttrState_Invalid) {
    return aCachedState;
  }

  if (aCachedState == nsContentUtils::eAutocompleteAttrState_Valid) {
    uint32_t atomCount = aAttr->GetAtomCount();
    for (uint32_t i = 0; i < atomCount; i++) {
      if (i != 0) {
        aResult.Append(' ');
      }
      aResult.Append(nsDependentAtomString(aAttr->AtomAt(i)));
    }
    nsContentUtils::ASCIIToLower(aResult);
    return aCachedState;
  }

  aResult.Truncate();

  mozilla::dom::AutocompleteInfo info;
  AutocompleteAttrState state =
    InternalSerializeAutocompleteAttribute(aAttr, info);
  if (state == eAutocompleteAttrState_Valid) {
    // Concatenate the info fields.
    aResult = info.mSection;

    if (!info.mAddressType.IsEmpty()) {
      if (!aResult.IsEmpty()) {
        aResult += ' ';
      }
      aResult += info.mAddressType;
    }

    if (!info.mContactType.IsEmpty()) {
      if (!aResult.IsEmpty()) {
        aResult += ' ';
      }
      aResult += info.mContactType;
    }

    if (!info.mFieldName.IsEmpty()) {
      if (!aResult.IsEmpty()) {
        aResult += ' ';
      }
      aResult += info.mFieldName;
    }
  }

  return state;
}

nsContentUtils::AutocompleteAttrState
nsContentUtils::SerializeAutocompleteAttribute(const nsAttrValue* aAttr,
                                               mozilla::dom::AutocompleteInfo& aInfo,
                                               AutocompleteAttrState aCachedState,
                                               bool aGrantAllValidValue)
{
  if (!aAttr ||
      aCachedState == nsContentUtils::eAutocompleteAttrState_Invalid) {
    return aCachedState;
  }

  return InternalSerializeAutocompleteAttribute(aAttr, aInfo, aGrantAllValidValue);
}

/**
 * Helper to validate the @autocomplete tokens.
 *
 * @return {AutocompleteAttrState} The state of the attribute (invalid/valid).
 */
nsContentUtils::AutocompleteAttrState
nsContentUtils::InternalSerializeAutocompleteAttribute(const nsAttrValue* aAttrVal,
                                                       mozilla::dom::AutocompleteInfo& aInfo,
                                                       bool aGrantAllValidValue)
{
  // No autocomplete attribute so we are done
  if (!aAttrVal) {
    return eAutocompleteAttrState_Invalid;
  }

  uint32_t numTokens = aAttrVal->GetAtomCount();
  if (!numTokens) {
    return eAutocompleteAttrState_Invalid;
  }

  uint32_t index = numTokens - 1;
  nsString tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
  AutocompleteCategory category;
  nsAttrValue enumValue;

  bool unsupported = false;
  if (!aGrantAllValidValue) {
    unsupported = enumValue.ParseEnumValue(tokenString,
                                           kAutocompleteUnsupportedFieldNameTable,
                                           false);
    if (unsupported) {
      return eAutocompleteAttrState_Invalid;
    }
  }

  nsAutoString str;
  bool result = enumValue.ParseEnumValue(tokenString, kAutocompleteFieldNameTable, false);
  if (result) {
    // Off/Automatic/Normal categories.
    if (enumValue.Equals(NS_LITERAL_STRING("off"), eIgnoreCase) ||
        enumValue.Equals(NS_LITERAL_STRING("on"), eIgnoreCase)) {
      if (numTokens > 1) {
        return eAutocompleteAttrState_Invalid;
      }
      enumValue.ToString(str);
      ASCIIToLower(str);
      aInfo.mFieldName.Assign(str);
      return eAutocompleteAttrState_Valid;
    }

    // Only allow on/off if form autofill @autocomplete values aren't enabled
    // and it doesn't grant all valid values.
    if (!sIsFormAutofillAutocompleteEnabled && !aGrantAllValidValue) {
      return eAutocompleteAttrState_Invalid;
    }

    // Normal category
    if (numTokens > 3) {
      return eAutocompleteAttrState_Invalid;
    }
    category = eAutocompleteCategory_NORMAL;
  } else { // Check if the last token is of the contact category instead.
    // Only allow on/off if form autofill @autocomplete values aren't enabled
    // and it doesn't grant all valid values.
    if (!sIsFormAutofillAutocompleteEnabled && !aGrantAllValidValue) {
      return eAutocompleteAttrState_Invalid;
    }

    result = enumValue.ParseEnumValue(tokenString, kAutocompleteContactFieldNameTable, false);
    if (!result || numTokens > 4) {
      return eAutocompleteAttrState_Invalid;
    }

    category = eAutocompleteCategory_CONTACT;
  }

  enumValue.ToString(str);
  ASCIIToLower(str);
  aInfo.mFieldName.Assign(str);

  // We are done if this was the only token.
  if (numTokens == 1) {
    return eAutocompleteAttrState_Valid;
  }

  --index;
  tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));

  if (category == eAutocompleteCategory_CONTACT) {
    if (!aGrantAllValidValue) {
      unsupported = enumValue.ParseEnumValue(tokenString,
                                             kAutocompleteUnsupportedContactFieldHintTable,
                                             false);
      if (unsupported) {
        return eAutocompleteAttrState_Invalid;
      }
    }


    nsAttrValue contactFieldHint;
    result = contactFieldHint.ParseEnumValue(tokenString, kAutocompleteContactFieldHintTable, false);
    if (result) {
      nsAutoString contactFieldHintString;
      contactFieldHint.ToString(contactFieldHintString);
      ASCIIToLower(contactFieldHintString);
      aInfo.mContactType.Assign(contactFieldHintString);
      if (index == 0) {
        return eAutocompleteAttrState_Valid;
      }
      --index;
      tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
    }
  }

  // Check for billing/shipping tokens
  nsAttrValue fieldHint;
  if (fieldHint.ParseEnumValue(tokenString, kAutocompleteFieldHintTable, false)) {
    nsString fieldHintString;
    fieldHint.ToString(fieldHintString);
    ASCIIToLower(fieldHintString);
    aInfo.mAddressType.Assign(fieldHintString);
    if (index == 0) {
      return eAutocompleteAttrState_Valid;
    }
    --index;
    tokenString = nsDependentAtomString(aAttrVal->AtomAt(index));
  }

  // Check for section-* token
  const nsDependentSubstring& section = Substring(tokenString, 0, 8);
  if (section.LowerCaseEqualsASCII("section-")) {
    ASCIIToLower(tokenString);
    aInfo.mSection.Assign(tokenString);
    if (index == 0) {
      return eAutocompleteAttrState_Valid;
    }
  }

  // Clear the fields as the autocomplete attribute is invalid.
  aInfo.mSection.Truncate();
  aInfo.mAddressType.Truncate();
  aInfo.mContactType.Truncate();
  aInfo.mFieldName.Truncate();

  return eAutocompleteAttrState_Invalid;
}

// Parse an integer according to HTML spec
int32_t
nsContentUtils::ParseHTMLInteger(const nsAString& aValue,
                                 ParseHTMLIntegerResultFlags *aResult)
{
  int result = eParseHTMLInteger_NoFlags;

  nsAString::const_iterator iter, end;
  aValue.BeginReading(iter);
  aValue.EndReading(end);

  while (iter != end && nsContentUtils::IsHTMLWhitespace(*iter)) {
    result |= eParseHTMLInteger_NonStandard;
    ++iter;
  }

  if (iter == end) {
    result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorNoValue;
    *aResult = (ParseHTMLIntegerResultFlags)result;
    return 0;
  }

  int sign = 1;
  if (*iter == char16_t('-')) {
    sign = -1;
    result |= eParseHTMLInteger_Negative;
    ++iter;
  } else if (*iter == char16_t('+')) {
    result |= eParseHTMLInteger_NonStandard;
    ++iter;
  }

  bool foundValue = false;
  CheckedInt32 value = 0;

  // Check for leading zeros first.
  uint64_t leadingZeros = 0;
  while (iter != end) {
    if (*iter != char16_t('0')) {
      break;
    }

    ++leadingZeros;
    foundValue = true;
    ++iter;
  }

  while (iter != end) {
    if (*iter >= char16_t('0') && *iter <= char16_t('9')) {
      value = (value * 10) + (*iter - char16_t('0')) * sign;
      ++iter;
      if (!value.isValid()) {
        result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorOverflow;
        break;
      }
      foundValue = true;
    } else if (*iter == char16_t('%')) {
      ++iter;
      result |= eParseHTMLInteger_IsPercent;
      break;
    } else {
      break;
    }
  }

  if (!foundValue) {
    result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorNoValue;
  }

  if (value.isValid() &&
       ((leadingZeros > 1 || (leadingZeros == 1 && !(value == 0))) ||
       (sign == -1 && value == 0))) {
    result |= eParseHTMLInteger_NonStandard;
  }

  if (iter != end) {
    result |= eParseHTMLInteger_DidNotConsumeAllInput;
  }

  *aResult = (ParseHTMLIntegerResultFlags)result;
  return value.isValid() ? value.value() : 0;
}

#define SKIP_WHITESPACE(iter, end_iter, end_res)                 \
  while ((iter) != (end_iter) && nsCRT::IsAsciiSpace(*(iter))) { \
    ++(iter);                                                    \
  }                                                              \
  if ((iter) == (end_iter)) {                                    \
    return (end_res);                                            \
  }

#define SKIP_ATTR_NAME(iter, end_iter)                            \
  while ((iter) != (end_iter) && !nsCRT::IsAsciiSpace(*(iter)) && \
         *(iter) != '=') {                                        \
    ++(iter);                                                     \
  }

bool
nsContentUtils::GetPseudoAttributeValue(const nsString& aSource, nsAtom *aName,
                                        nsAString& aValue)
{
  aValue.Truncate();

  const char16_t *start = aSource.get();
  const char16_t *end = start + aSource.Length();
  const char16_t *iter;

  while (start != end) {
    SKIP_WHITESPACE(start, end, false)
    iter = start;
    SKIP_ATTR_NAME(iter, end)

    if (start == iter) {
      return false;
    }

    // Remember the attr name.
    const nsDependentSubstring & attrName = Substring(start, iter);

    // Now check whether this is a valid name="value" pair.
    start = iter;
    SKIP_WHITESPACE(start, end, false)
    if (*start != '=') {
      // No '=', so this is not a name="value" pair.  We don't know
      // what it is, and we have no way to handle it.
      return false;
    }

    // Have to skip the value.
    ++start;
    SKIP_WHITESPACE(start, end, false)
    char16_t q = *start;
    if (q != kQuote && q != kApostrophe) {
      // Not a valid quoted value, so bail.
      return false;
    }

    ++start;  // Point to the first char of the value.
    iter = start;

    while (iter != end && *iter != q) {
      ++iter;
    }

    if (iter == end) {
      // Oops, unterminated quoted string.
      return false;
    }

    // At this point attrName holds the name of the "attribute" and
    // the value is between start and iter.

    if (aName->Equals(attrName)) {
      // We'll accumulate as many characters as possible (until we hit either
      // the end of the string or the beginning of an entity). Chunks will be
      // delimited by start and chunkEnd.
      const char16_t *chunkEnd = start;
      while (chunkEnd != iter) {
        if (*chunkEnd == kLessThan) {
          aValue.Truncate();

          return false;
        }

        if (*chunkEnd == kAmpersand) {
          aValue.Append(start, chunkEnd - start);

          const char16_t *afterEntity = nullptr;
          char16_t result[2];
          uint32_t count =
            MOZ_XMLTranslateEntity(reinterpret_cast<const char*>(chunkEnd),
                                   reinterpret_cast<const char*>(iter),
                                   reinterpret_cast<const char**>(&afterEntity),
                                   result);
          if (count == 0) {
            aValue.Truncate();

            return false;
          }

          aValue.Append(result, count);

          // Advance to after the entity and begin a new chunk.
          start = chunkEnd = afterEntity;
        }
        else {
          ++chunkEnd;
        }
      }

      // Append remainder.
      aValue.Append(start, iter - start);

      return true;
    }

    // Resume scanning after the end of the attribute value (past the quote
    // char).
    start = iter + 1;
  }

  return false;
}

bool
nsContentUtils::IsJavaScriptLanguage(const nsString& aName)
{
  return aName.LowerCaseEqualsLiteral("javascript") ||
         aName.LowerCaseEqualsLiteral("livescript") ||
         aName.LowerCaseEqualsLiteral("mocha") ||
         aName.LowerCaseEqualsLiteral("javascript1.0") ||
         aName.LowerCaseEqualsLiteral("javascript1.1") ||
         aName.LowerCaseEqualsLiteral("javascript1.2") ||
         aName.LowerCaseEqualsLiteral("javascript1.3") ||
         aName.LowerCaseEqualsLiteral("javascript1.4") ||
         aName.LowerCaseEqualsLiteral("javascript1.5");
}

void
nsContentUtils::SplitMimeType(const nsAString& aValue, nsString& aType,
                              nsString& aParams)
{
  aType.Truncate();
  aParams.Truncate();
  int32_t semiIndex = aValue.FindChar(char16_t(';'));
  if (-1 != semiIndex) {
    aType = Substring(aValue, 0, semiIndex);
    aParams = Substring(aValue, semiIndex + 1,
                       aValue.Length() - (semiIndex + 1));
    aParams.StripWhitespace();
  }
  else {
    aType = aValue;
  }
  aType.StripWhitespace();
}

nsresult
nsContentUtils::IsUserIdle(uint32_t aRequestedIdleTimeInMS, bool* aUserIsIdle)
{
  nsresult rv;
  nsCOMPtr<nsIIdleService> idleService =
    do_GetService("@mozilla.org/widget/idleservice;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  uint32_t idleTimeInMS;
  rv = idleService->GetIdleTime(&idleTimeInMS);
  NS_ENSURE_SUCCESS(rv, rv);

  *aUserIsIdle = idleTimeInMS >= aRequestedIdleTimeInMS;
  return NS_OK;
}

/**
* A helper function that parses a sandbox attribute (of an <iframe> or a CSP
* directive) and converts it to the set of flags used internally.
*
* @param aSandboxAttr  the sandbox attribute
* @return              the set of flags (SANDBOXED_NONE if aSandboxAttr is
*                      null)
*/
uint32_t
nsContentUtils::ParseSandboxAttributeToFlags(const nsAttrValue* aSandboxAttr)
{
  if (!aSandboxAttr) {
    return SANDBOXED_NONE;
  }

  uint32_t out = SANDBOX_ALL_FLAGS;

#define SANDBOX_KEYWORD(string, atom, flags)                  \
  if (aSandboxAttr->Contains(nsGkAtoms::atom, eIgnoreCase)) { \
    out &= ~(flags);                                          \
  }
#include "IframeSandboxKeywordList.h"
#undef SANDBOX_KEYWORD

  return out;
}

/**
* A helper function that checks if a string matches a valid sandbox flag.
*
* @param aFlag   the potential sandbox flag.
* @return        true if the flag is a sandbox flag.
*/
bool
nsContentUtils::IsValidSandboxFlag(const nsAString& aFlag)
{
#define SANDBOX_KEYWORD(string, atom, flags)                                  \
  if (EqualsIgnoreASCIICase(nsDependentAtomString(nsGkAtoms::atom), aFlag)) { \
    return true;                                                              \
  }
#include "IframeSandboxKeywordList.h"
#undef SANDBOX_KEYWORD
  return false;
}

/**
 * A helper function that returns a string attribute corresponding to the
 * sandbox flags.
 *
 * @param aFlags    the sandbox flags
 * @param aString   the attribute corresponding to the flags (null if aFlags
 *                  is zero)
 */
void
nsContentUtils::SandboxFlagsToString(uint32_t aFlags, nsAString& aString)
{
  if (!aFlags) {
    SetDOMStringToNull(aString);
    return;
  }

  aString.Truncate();

#define SANDBOX_KEYWORD(string, atom, flags)                \
  if (!(aFlags & (flags))) {                                \
    if (!aString.IsEmpty()) {                               \
      aString.AppendLiteral(u" ");                          \
    }                                                       \
    aString.Append(nsDependentAtomString(nsGkAtoms::atom)); \
  }
#include "IframeSandboxKeywordList.h"
#undef SANDBOX_KEYWORD
}

nsIBidiKeyboard*
nsContentUtils::GetBidiKeyboard()
{
  if (!sBidiKeyboard) {
    nsresult rv = CallGetService("@mozilla.org/widget/bidikeyboard;1", &sBidiKeyboard);
    if (NS_FAILED(rv)) {
      sBidiKeyboard = nullptr;
    }
  }
  return sBidiKeyboard;
}

/**
 * This is used to determine whether a character is in one of the classes
 * which CSS says should be part of the first-letter.  Currently, that is
 * all punctuation classes (P*).  Note that this is a change from CSS2
 * which excluded Pc and Pd.
 *
 * https://www.w3.org/TR/css-pseudo-4/#first-letter-pseudo
 * "Punctuation (i.e, characters that belong to the Punctuation (P*) Unicode
 *  general category [UAX44]) [...]"
 */

// static
bool
nsContentUtils::IsFirstLetterPunctuation(uint32_t aChar)
{
  switch (mozilla::unicode::GetGeneralCategory(aChar)) {
    case HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION: /* Pc */
    case HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION:    /* Pd */
    case HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION:   /* Pe */
    case HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION:   /* Pf */
    case HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION: /* Pi */
    case HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION:   /* Po */
    case HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION:    /* Ps */
      return true;
    default:
      return false;
  }
}

// static
bool
nsContentUtils::IsFirstLetterPunctuationAt(const nsTextFragment* aFrag, uint32_t aOffset)
{
  char16_t h = aFrag->CharAt(aOffset);
  if (!IS_SURROGATE(h)) {
    return IsFirstLetterPunctuation(h);
  }
  if (NS_IS_HIGH_SURROGATE(h) && aOffset + 1 < aFrag->GetLength()) {
    char16_t l = aFrag->CharAt(aOffset + 1);
    if (NS_IS_LOW_SURROGATE(l)) {
      return IsFirstLetterPunctuation(SURROGATE_TO_UCS4(h, l));
    }
  }
  return false;
}

// static
bool nsContentUtils::IsAlphanumeric(uint32_t aChar)
{
  nsUGenCategory cat = mozilla::unicode::GetGenCategory(aChar);

  return (cat == nsUGenCategory::kLetter || cat == nsUGenCategory::kNumber);
}

// static
bool nsContentUtils::IsAlphanumericAt(const nsTextFragment* aFrag, uint32_t aOffset)
{
  char16_t h = aFrag->CharAt(aOffset);
  if (!IS_SURROGATE(h)) {
    return IsAlphanumeric(h);
  }
  if (NS_IS_HIGH_SURROGATE(h) && aOffset + 1 < aFrag->GetLength()) {
    char16_t l = aFrag->CharAt(aOffset + 1);
    if (NS_IS_LOW_SURROGATE(l)) {
      return IsAlphanumeric(SURROGATE_TO_UCS4(h, l));
    }
  }
  return false;
}

/* static */
bool
nsContentUtils::IsHTMLWhitespace(char16_t aChar)
{
  return aChar == char16_t(0x0009) ||
         aChar == char16_t(0x000A) ||
         aChar == char16_t(0x000C) ||
         aChar == char16_t(0x000D) ||
         aChar == char16_t(0x0020);
}

/* static */
bool
nsContentUtils::IsHTMLWhitespaceOrNBSP(char16_t aChar)
{
  return IsHTMLWhitespace(aChar) || aChar == char16_t(0xA0);
}

/* static */
bool
nsContentUtils::IsHTMLBlock(nsIContent* aContent)
{
  return aContent->IsAnyOfHTMLElements(nsGkAtoms::address,
                                       nsGkAtoms::article,
                                       nsGkAtoms::aside,
                                       nsGkAtoms::blockquote,
                                       nsGkAtoms::center,
                                       nsGkAtoms::dir,
                                       nsGkAtoms::div,
                                       nsGkAtoms::dl, // XXX why not dt and dd?
                                       nsGkAtoms::fieldset,
                                       nsGkAtoms::figure, // XXX shouldn't figcaption be on this list
                                       nsGkAtoms::footer,
                                       nsGkAtoms::form,
                                       nsGkAtoms::h1,
                                       nsGkAtoms::h2,
                                       nsGkAtoms::h3,
                                       nsGkAtoms::h4,
                                       nsGkAtoms::h5,
                                       nsGkAtoms::h6,
                                       nsGkAtoms::header,
                                       nsGkAtoms::hgroup,
                                       nsGkAtoms::hr,
                                       nsGkAtoms::li,
                                       nsGkAtoms::listing,
                                       nsGkAtoms::menu,
                                       nsGkAtoms::multicol, // XXX get rid of this one?
                                       nsGkAtoms::nav,
                                       nsGkAtoms::ol,
                                       nsGkAtoms::p,
                                       nsGkAtoms::pre,
                                       nsGkAtoms::section,
                                       nsGkAtoms::table,
                                       nsGkAtoms::ul,
                                       nsGkAtoms::xmp);
}

/* static */
bool
nsContentUtils::ParseIntMarginValue(const nsAString& aString, nsIntMargin& result)
{
  nsAutoString marginStr(aString);
  marginStr.CompressWhitespace(true, true);
  if (marginStr.IsEmpty()) {
    return false;
  }

  int32_t start = 0, end = 0;
  for (int count = 0; count < 4; count++) {
    if ((uint32_t)end >= marginStr.Length())
      return false;

    // top, right, bottom, left
    if (count < 3)
      end = Substring(marginStr, start).FindChar(',');
    else
      end = Substring(marginStr, start).Length();

    if (end <= 0)
      return false;

    nsresult ec;
    int32_t val = nsString(Substring(marginStr, start, end)).ToInteger(&ec);
    if (NS_FAILED(ec))
      return false;

    switch(count) {
      case 0:
        result.top = val;
      break;
      case 1:
        result.right = val;
      break;
      case 2:
        result.bottom = val;
      break;
      case 3:
        result.left = val;
      break;
    }
    start += end + 1;
  }
  return true;
}

// static
int32_t
nsContentUtils::ParseLegacyFontSize(const nsAString& aValue)
{
  nsAString::const_iterator iter, end;
  aValue.BeginReading(iter);
  aValue.EndReading(end);

  while (iter != end && nsContentUtils::IsHTMLWhitespace(*iter)) {
    ++iter;
  }

  if (iter == end) {
    return 0;
  }

  bool relative = false;
  bool negate = false;
  if (*iter == char16_t('-')) {
    relative = true;
    negate = true;
    ++iter;
  } else if (*iter == char16_t('+')) {
    relative = true;
    ++iter;
  }

  if (iter == end || *iter < char16_t('0') || *iter > char16_t('9')) {
    return 0;
  }

  // We don't have to worry about overflow, since we can bail out as soon as
  // we're bigger than 7.
  int32_t value = 0;
  while (iter != end && *iter >= char16_t('0') && *iter <= char16_t('9')) {
    value = 10*value + (*iter - char16_t('0'));
    if (value >= 7) {
      break;
    }
    ++iter;
  }

  if (relative) {
    if (negate) {
      value = 3 - value;
    } else {
      value = 3 + value;
    }
  }

  return clamped(value, 1, 7);
}

/* static */
void
nsContentUtils::GetOfflineAppManifest(nsIDocument *aDocument, nsIURI **aURI)
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aDocument);
  *aURI = nullptr;

  if (aDocument->GetController().isSome()) {
    return;
  }

  Element* docElement = aDocument->GetRootElement();
  if (!docElement) {
    return;
  }

  nsAutoString manifestSpec;
  docElement->GetAttr(kNameSpaceID_None, nsGkAtoms::manifest, manifestSpec);

  // Manifest URIs can't have fragment identifiers.
  if (manifestSpec.IsEmpty() ||
      manifestSpec.Contains('#')) {
    return;
  }

  nsContentUtils::NewURIWithDocumentCharset(aURI, manifestSpec,
                                            aDocument,
                                            aDocument->GetDocBaseURI());
}

/* static */
bool
nsContentUtils::OfflineAppAllowed(nsIURI *aURI)
{
  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
  if (!updateService) {
    return false;
  }

  bool allowed;
  nsresult rv =
    updateService->OfflineAppAllowedForURI(aURI,
                                           Preferences::GetRootBranch(),
                                           &allowed);
  return NS_SUCCEEDED(rv) && allowed;
}

/* static */
bool
nsContentUtils::OfflineAppAllowed(nsIPrincipal *aPrincipal)
{
  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
  if (!updateService) {
    return false;
  }

  bool allowed;
  nsresult rv = updateService->OfflineAppAllowed(aPrincipal,
                                                 Preferences::GetRootBranch(),
                                                 &allowed);
  return NS_SUCCEEDED(rv) && allowed;
}

bool
nsContentUtils::MaybeAllowOfflineAppByDefault(nsIPrincipal *aPrincipal)
{
  if (!Preferences::GetRootBranch())
    return false;

  nsresult rv;

  bool allowedByDefault;
  rv = Preferences::GetRootBranch()->GetBoolPref(
    "offline-apps.allow_by_default", &allowedByDefault);
  if (NS_FAILED(rv))
    return false;

  if (!allowedByDefault)
    return false;

  nsCOMPtr<nsIOfflineCacheUpdateService> updateService =
    do_GetService(NS_OFFLINECACHEUPDATESERVICE_CONTRACTID);
  if (!updateService) {
    return false;
  }

  rv = updateService->AllowOfflineApp(aPrincipal);
  return NS_SUCCEEDED(rv);
}

// static
void
nsContentUtils::Shutdown()
{
  sInitialized = false;

  nsHTMLTags::ReleaseTable();

  NS_IF_RELEASE(sContentPolicyService);
  sTriedToGetContentPolicy = false;
  uint32_t i;
  for (i = 0; i < PropertiesFile_COUNT; ++i)
    NS_IF_RELEASE(sStringBundles[i]);

  NS_IF_RELEASE(sStringBundleService);
  NS_IF_RELEASE(sConsoleService);
  NS_IF_RELEASE(sXPConnect);
  NS_IF_RELEASE(sSecurityManager);
  NS_IF_RELEASE(sSystemPrincipal);
  NS_IF_RELEASE(sNullSubjectPrincipal);
  NS_IF_RELEASE(sIOService);
  NS_IF_RELEASE(sUUIDGenerator);
  sLineBreaker = nullptr;
  sWordBreaker = nullptr;
  NS_IF_RELEASE(sBidiKeyboard);

  delete sAtomEventTable;
  sAtomEventTable = nullptr;
  delete sStringEventTable;
  sStringEventTable = nullptr;
  delete sUserDefinedEvents;
  sUserDefinedEvents = nullptr;

  if (sEventListenerManagersHash) {
    NS_ASSERTION(sEventListenerManagersHash->EntryCount() == 0,
                 "Event listener manager hash not empty at shutdown!");

    // See comment above.

    // However, we have to handle this table differently.  If it still
    // has entries, we want to leak it too, so that we can keep it alive
    // in case any elements are destroyed.  Because if they are, we need
    // their event listener managers to be destroyed too, or otherwise
    // it could leave dangling references in DOMClassInfo's preserved
    // wrapper table.

    if (sEventListenerManagersHash->EntryCount() == 0) {
      delete sEventListenerManagersHash;
      sEventListenerManagersHash = nullptr;
    }
  }

  NS_ASSERTION(!sBlockedScriptRunners ||
               sBlockedScriptRunners->Length() == 0,
               "How'd this happen?");
  delete sBlockedScriptRunners;
  sBlockedScriptRunners = nullptr;

  delete sShiftText;
  sShiftText = nullptr;
  delete sControlText;
  sControlText = nullptr;
  delete sMetaText;
  sMetaText = nullptr;
  delete sOSText;
  sOSText = nullptr;
  delete sAltText;
  sAltText = nullptr;
  delete sModifierSeparator;
  sModifierSeparator = nullptr;

  delete sJSBytecodeMimeType;
  sJSBytecodeMimeType = nullptr;

  NS_IF_RELEASE(sSameOriginChecker);

  if (sUserInteractionObserver) {
    sUserInteractionObserver->Shutdown();
    NS_RELEASE(sUserInteractionObserver);
  }

  HTMLInputElement::Shutdown();
  nsMappedAttributes::Shutdown();
}

/**
 * Checks whether two nodes come from the same origin. aTrustedNode is
 * considered 'safe' in that a user can operate on it and that it isn't
 * a js-object that implements nsIDOMNode.
 * Never call this function with the first node provided by script, it
 * must always be known to be a 'real' node!
 */
// static
nsresult
nsContentUtils::CheckSameOrigin(const nsINode *aTrustedNode,
                                nsIDOMNode *aUnTrustedNode)
{
  MOZ_ASSERT(aTrustedNode);

  // Make sure it's a real node.
  nsCOMPtr<nsINode> unTrustedNode = do_QueryInterface(aUnTrustedNode);
  NS_ENSURE_TRUE(unTrustedNode, NS_ERROR_UNEXPECTED);
  return CheckSameOrigin(aTrustedNode, unTrustedNode);
}

nsresult
nsContentUtils::CheckSameOrigin(const nsINode* aTrustedNode,
                                const nsINode* unTrustedNode)
{
  MOZ_ASSERT(aTrustedNode);
  MOZ_ASSERT(unTrustedNode);

  /*
   * Get hold of each node's principal
   */

  nsIPrincipal* trustedPrincipal = aTrustedNode->NodePrincipal();
  nsIPrincipal* unTrustedPrincipal = unTrustedNode->NodePrincipal();

  if (trustedPrincipal == unTrustedPrincipal) {
    return NS_OK;
  }

  bool equal;
  // XXXbz should we actually have a Subsumes() check here instead?  Or perhaps
  // a separate method for that, with callers using one or the other?
  if (NS_FAILED(trustedPrincipal->Equals(unTrustedPrincipal, &equal)) ||
      !equal) {
    return NS_ERROR_DOM_PROP_ACCESS_DENIED;
  }

  return NS_OK;
}

// static
bool
nsContentUtils::CanCallerAccess(nsIPrincipal* aSubjectPrincipal,
                                nsIPrincipal* aPrincipal)
{
  bool subsumes;
  nsresult rv = aSubjectPrincipal->Subsumes(aPrincipal, &subsumes);
  NS_ENSURE_SUCCESS(rv, false);

  if (subsumes) {
    return true;
  }

  // The subject doesn't subsume aPrincipal. Allow access only if the subject
  // is chrome.
  return IsCallerChrome();
}

// static
bool
nsContentUtils::CanCallerAccess(nsIDOMNode *aNode)
{
  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
  NS_ENSURE_TRUE(node, false);
  return CanCallerAccess(node);
}

// static
bool
nsContentUtils::CanCallerAccess(nsINode* aNode)
{
  return CanCallerAccess(SubjectPrincipal(), aNode->NodePrincipal());
}

// static
bool
nsContentUtils::CanCallerAccess(nsPIDOMWindowInner* aWindow)
{
  nsCOMPtr<nsIScriptObjectPrincipal> scriptObject = do_QueryInterface(aWindow);
  NS_ENSURE_TRUE(scriptObject, false);

  return CanCallerAccess(SubjectPrincipal(), scriptObject->GetPrincipal());
}

// static
bool
nsContentUtils::PrincipalHasPermission(nsIPrincipal* aPrincipal, const nsAtom* aPerm)
{
  // Chrome gets access by default.
  if (IsSystemPrincipal(aPrincipal)) {
    return true;
  }

  // Otherwise, only allow if caller is an addon with the permission.
  return BasePrincipal::Cast(aPrincipal)->AddonHasPermission(aPerm);
}

// static
bool
nsContentUtils::CallerHasPermission(JSContext* aCx, const nsAtom* aPerm)
{
  return PrincipalHasPermission(SubjectPrincipal(aCx), aPerm);
}

// static
nsIPrincipal*
nsContentUtils::GetAttrTriggeringPrincipal(nsIContent* aContent, const nsAString& aAttrValue,
                                           nsIPrincipal* aSubjectPrincipal)
{
  nsIPrincipal* contentPrin = aContent ? aContent->NodePrincipal() : nullptr;

  // If the subject principal is the same as the content principal, or no
  // explicit subject principal was provided, we don't need to do any further
  // checks. Just return the content principal.
  if (contentPrin == aSubjectPrincipal || !aSubjectPrincipal) {
    return contentPrin;
  }

  // If the attribute value is empty, it's not an absolute URL, so don't bother
  // with more expensive checks.
  if (!aAttrValue.IsEmpty() &&
      IsAbsoluteURL(NS_ConvertUTF16toUTF8(aAttrValue))) {
    return aSubjectPrincipal;
  }

  return contentPrin;
}

// static
bool
nsContentUtils::IsAbsoluteURL(const nsACString& aURL)
{
  nsAutoCString scheme;
  if (NS_FAILED(net_ExtractURLScheme(aURL, scheme))) {
    // If we can't extract a scheme, it's not an absolute URL.
    return false;
  }

  // If it parses as an absolute StandardURL, it's definitely an absolute URL,
  // so no need to check with the IO service.
  if (net_IsAbsoluteURL(aURL)) {
    return true;
  }

  uint32_t flags;
  if (NS_SUCCEEDED(sIOService->GetProtocolFlags(scheme.get(), &flags))) {
    return flags & nsIProtocolHandler::URI_NORELATIVE;
  }

  return false;
}

//static
bool
nsContentUtils::InProlog(nsINode *aNode)
{
  NS_PRECONDITION(aNode, "missing node to nsContentUtils::InProlog");

  nsINode* parent = aNode->GetParentNode();
  if (!parent || !parent->IsNodeOfType(nsINode::eDOCUMENT)) {
    return false;
  }

  nsIDocument* doc = static_cast<nsIDocument*>(parent);
  nsIContent* root = doc->GetRootElement();

  return !root || doc->ComputeIndexOf(aNode) < doc->ComputeIndexOf(root);
}

nsIDocument*
nsContentUtils::GetDocumentFromCaller()
{
  AutoJSContext cx;

  nsCOMPtr<nsPIDOMWindowInner> win =
    do_QueryInterface(nsJSUtils::GetStaticScriptGlobal(JS::CurrentGlobalOrNull(cx)));
  if (!win) {
    return nullptr;
  }

  return win->GetExtantDoc();
}

bool
nsContentUtils::IsCallerChrome()
{
  MOZ_ASSERT(NS_IsMainThread());
  if (SubjectPrincipal() == sSystemPrincipal) {
    return true;
  }

  // If the check failed, look for UniversalXPConnect on the cx compartment.
  return xpc::IsUniversalXPConnectEnabled(GetCurrentJSContext());
}

/* static */
bool
nsContentUtils::ShouldResistFingerprinting()
{
  return DOMPrefs::ResistFingerprintingEnabled();
}

bool
nsContentUtils::ShouldResistFingerprinting(nsIDocShell* aDocShell)
{
  if (!aDocShell) {
    return false;
  }
  return ShouldResistFingerprinting(aDocShell->GetDocument());
}

/* static */
bool
nsContentUtils::ShouldResistFingerprinting(nsIDocument* aDoc) {
  if (!aDoc) {
    return false;
  }
  bool isChrome = nsContentUtils::IsChromeDoc(aDoc);
  return !isChrome && ShouldResistFingerprinting();
}

/* static */
void
nsContentUtils::CalcRoundedWindowSizeForResistingFingerprinting(int32_t  aChromeWidth,
                                                                int32_t  aChromeHeight,
                                                                int32_t  aScreenWidth,
                                                                int32_t  aScreenHeight,
                                                                int32_t  aInputWidth,
                                                                int32_t  aInputHeight,
                                                                bool     aSetOuterWidth,
                                                                bool     aSetOuterHeight,
                                                                int32_t* aOutputWidth,
                                                                int32_t* aOutputHeight)
{
  MOZ_ASSERT(aOutputWidth);
  MOZ_ASSERT(aOutputHeight);

  int32_t availContentWidth  = 0;
  int32_t availContentHeight = 0;

  availContentWidth = std::min(sPrivacyMaxInnerWidth,
                               aScreenWidth - aChromeWidth);
#ifdef MOZ_WIDGET_GTK
  // In the GTK window, it will not report outside system decorations
  // when we get available window size, see Bug 581863. So, we leave a
  // 40 pixels space for them when calculating the available content
  // height. It is not necessary for the width since the content width
  // is usually pretty much the same as the chrome width.
  availContentHeight = std::min(sPrivacyMaxInnerHeight,
                                (-40 + aScreenHeight) - aChromeHeight);
#else
  availContentHeight = std::min(sPrivacyMaxInnerHeight,
                                aScreenHeight - aChromeHeight);
#endif

  // Ideally, we'd like to round window size to 1000x1000, but the
  // screen space could be too small to accommodate this size in some
  // cases. If it happens, we would round the window size to the nearest
  // 200x100.
  availContentWidth = availContentWidth - (availContentWidth % 200);
  availContentHeight = availContentHeight - (availContentHeight % 100);

  // If aIsOuter is true, we are setting the outer window. So we
  // have to consider the chrome UI.
  int32_t chromeOffsetWidth = aSetOuterWidth ? aChromeWidth : 0;
  int32_t chromeOffsetHeight = aSetOuterHeight ? aChromeHeight : 0;
  int32_t resultWidth = 0, resultHeight = 0;

  // if the original size is greater than the maximum available size, we set
  // it to the maximum size. And if the original value is less than the
  // minimum rounded size, we set it to the minimum 200x100.
  if (aInputWidth > (availContentWidth + chromeOffsetWidth)) {
    resultWidth = availContentWidth + chromeOffsetWidth;
  } else if (aInputWidth < (200 + chromeOffsetWidth)) {
    resultWidth = 200 + chromeOffsetWidth;
  } else {
    // Otherwise, we round the window to the nearest upper rounded 200x100.
    resultWidth = NSToIntCeil((aInputWidth - chromeOffsetWidth) / 200.0) * 200 + chromeOffsetWidth;
  }

  if (aInputHeight > (availContentHeight + chromeOffsetHeight)) {
    resultHeight = availContentHeight + chromeOffsetHeight;
  } else if (aInputHeight < (100 + chromeOffsetHeight)) {
    resultHeight = 100 + chromeOffsetHeight;
  } else {
    resultHeight = NSToIntCeil((aInputHeight - chromeOffsetHeight) / 100.0) * 100 + chromeOffsetHeight;
  }

  *aOutputWidth = resultWidth;
  *aOutputHeight = resultHeight;
}

bool
nsContentUtils::ThreadsafeIsCallerChrome()
{
  return NS_IsMainThread()
           ? IsCallerChrome()
           : IsCurrentThreadRunningChromeWorker();
}

bool
nsContentUtils::IsCallerContentXBL()
{
  JSContext *cx = GetCurrentJSContext();
  if (!cx)
    return false;

  JS::Realm* realm = JS::GetCurrentRealmOrNull(cx);
  if (!realm)
    return false;

  // For remote XUL, we run XBL in the XUL scope. Given that we care about
  // compat and not security for remote XUL, just always claim to be XBL.
  if (!xpc::AllowContentXBLScope(realm)) {
    DebugOnly<JSCompartment*> c = JS::GetCompartmentForRealm(realm);
    MOZ_ASSERT(nsContentUtils::AllowXULXBLForPrincipal(xpc::GetCompartmentPrincipal(c)));
    return true;
  }

  return xpc::IsContentXBLScope(realm);
}

bool
nsContentUtils::IsSystemCaller(JSContext* aCx)
{
  // Note that SubjectPrincipal() assumes we are in a compartment here.
  return SubjectPrincipal(aCx) == sSystemPrincipal;
}

bool
nsContentUtils::ThreadsafeIsSystemCaller(JSContext* aCx)
{
  CycleCollectedJSContext* ccjscx = CycleCollectedJSContext::Get();
  MOZ_ASSERT(ccjscx->Context() == aCx);

  return ccjscx->IsSystemCaller();
}

// static
bool
nsContentUtils::LookupBindingMember(JSContext* aCx, nsIContent *aContent,
                                    JS::Handle<jsid> aId,
                                    JS::MutableHandle<JS::PropertyDescriptor> aDesc)
{
  nsXBLBinding* binding = aContent->GetXBLBinding();
  if (!binding)
    return true;
  return binding->LookupMember(aCx, aId, aDesc);
}

// static
nsINode*
nsContentUtils::GetCrossDocParentNode(nsINode* aChild)
{
  NS_PRECONDITION(aChild, "The child is null!");

  nsINode* parent = aChild->GetParentNode();
  if (parent && parent->IsContent() && aChild->IsContent()) {
    parent = aChild->AsContent()->GetFlattenedTreeParent();
  }

  if (parent || !aChild->IsNodeOfType(nsINode::eDOCUMENT))
    return parent;

  nsIDocument* doc = static_cast<nsIDocument*>(aChild);
  nsIDocument* parentDoc = doc->GetParentDocument();
  return parentDoc ? parentDoc->FindContentForSubDocument(doc) : nullptr;
}

// static
bool
nsContentUtils::ContentIsDescendantOf(const nsINode* aPossibleDescendant,
                                      const nsINode* aPossibleAncestor)
{
  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");

  do {
    if (aPossibleDescendant == aPossibleAncestor)
      return true;
    aPossibleDescendant = aPossibleDescendant->GetParentNode();
  } while (aPossibleDescendant);

  return false;
}

bool
nsContentUtils::ContentIsHostIncludingDescendantOf(
  const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor)
{
  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");

  do {
    if (aPossibleDescendant == aPossibleAncestor)
      return true;
    if (aPossibleDescendant->NodeType() == nsINode::DOCUMENT_FRAGMENT_NODE) {
      aPossibleDescendant =
        static_cast<const DocumentFragment*>(aPossibleDescendant)->GetHost();
    } else {
      aPossibleDescendant = aPossibleDescendant->GetParentNode();
    }
  } while (aPossibleDescendant);

  return false;
}

bool
nsContentUtils::ContentIsShadowIncludingDescendantOf(
  const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor)
{
  MOZ_ASSERT(aPossibleDescendant, "The possible descendant is null!");
  MOZ_ASSERT(aPossibleAncestor, "The possible ancestor is null!");

  if (aPossibleAncestor == aPossibleDescendant->GetComposedDoc()) {
    return true;
  }

  do {
    if (aPossibleDescendant == aPossibleAncestor) {
      return true;
    }

    if (aPossibleDescendant->NodeType() == nsINode::DOCUMENT_FRAGMENT_NODE) {
      ShadowRoot* shadowRoot =
        ShadowRoot::FromNode(const_cast<nsINode*>(aPossibleDescendant));
      aPossibleDescendant = shadowRoot ? shadowRoot->GetHost() : nullptr;
    } else {
      aPossibleDescendant = aPossibleDescendant->GetParentNode();
    }
  } while (aPossibleDescendant);

  return false;
}

// static
bool
nsContentUtils::ContentIsCrossDocDescendantOf(nsINode* aPossibleDescendant,
                                              nsINode* aPossibleAncestor)
{
  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");

  do {
    if (aPossibleDescendant == aPossibleAncestor)
      return true;

    aPossibleDescendant = GetCrossDocParentNode(aPossibleDescendant);
  } while (aPossibleDescendant);

  return false;
}

// static
bool
nsContentUtils::ContentIsFlattenedTreeDescendantOf(
  const nsINode* aPossibleDescendant,
  const nsINode* aPossibleAncestor)
{
  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");

  do {
    if (aPossibleDescendant == aPossibleAncestor) {
      return true;
    }
    aPossibleDescendant = aPossibleDescendant->GetFlattenedTreeParentNode();
  } while (aPossibleDescendant);

  return false;
}

// static
bool
nsContentUtils::ContentIsFlattenedTreeDescendantOfForStyle(
  const nsINode* aPossibleDescendant,
  const nsINode* aPossibleAncestor)
{
  NS_PRECONDITION(aPossibleDescendant, "The possible descendant is null!");
  NS_PRECONDITION(aPossibleAncestor, "The possible ancestor is null!");

  do {
    if (aPossibleDescendant == aPossibleAncestor) {
      return true;
    }
    aPossibleDescendant =
      aPossibleDescendant->GetFlattenedTreeParentNodeForStyle();
  } while (aPossibleDescendant);

  return false;
}

// static
nsINode*
nsContentUtils::Retarget(nsINode* aTargetA, nsINode* aTargetB)
{
  while (true && aTargetA) {
    // If A's root is not a shadow root...
    nsINode* root = aTargetA->SubtreeRoot();
    if (!root->IsShadowRoot()) {
      // ...then return A.
      return aTargetA;
    }

    // or A's root is a shadow-including inclusive ancestor of B...
    if (nsContentUtils::ContentIsShadowIncludingDescendantOf(aTargetB, root)) {
      // ...then return A.
      return aTargetA;
    }

    aTargetA = ShadowRoot::FromNode(root)->GetHost();
  }

  return nullptr;
}

// static
nsresult
nsContentUtils::GetAncestors(nsINode* aNode,
                             nsTArray<nsINode*>& aArray)
{
  while (aNode) {
    aArray.AppendElement(aNode);
    aNode = aNode->GetParentNode();
  }
  return NS_OK;
}

// static
nsresult
nsContentUtils::GetAncestorsAndOffsets(nsIDOMNode* aNode,
                                       int32_t aOffset,
                                       nsTArray<nsIContent*>* aAncestorNodes,
                                       nsTArray<int32_t>* aAncestorOffsets)
{
  NS_ENSURE_ARG_POINTER(aNode);

  nsCOMPtr<nsIContent> content(do_QueryInterface(aNode));

  if (!content) {
    return NS_ERROR_FAILURE;
  }

  if (!aAncestorNodes->IsEmpty()) {
    NS_WARNING("aAncestorNodes is not empty");
    aAncestorNodes->Clear();
  }

  if (!aAncestorOffsets->IsEmpty()) {
    NS_WARNING("aAncestorOffsets is not empty");
    aAncestorOffsets->Clear();
  }

  // insert the node itself
  aAncestorNodes->AppendElement(content.get());
  aAncestorOffsets->AppendElement(aOffset);

  // insert all the ancestors
  nsIContent* child = content;
  nsIContent* parent = child->GetParent();
  while (parent) {
    aAncestorNodes->AppendElement(parent);
    aAncestorOffsets->AppendElement(parent->ComputeIndexOf(child));
    child = parent;
    parent = parent->GetParent();
  }

  return NS_OK;
}

// static
nsresult
nsContentUtils::GetCommonAncestor(nsIDOMNode *aNode,
                                  nsIDOMNode *aOther,
                                  nsIDOMNode** aCommonAncestor)
{
  *aCommonAncestor = nullptr;

  nsCOMPtr<nsINode> node1 = do_QueryInterface(aNode);
  nsCOMPtr<nsINode> node2 = do_QueryInterface(aOther);

  NS_ENSURE_TRUE(node1 && node2, NS_ERROR_UNEXPECTED);

  nsINode* common = GetCommonAncestor(node1, node2);
  NS_ENSURE_TRUE(common, NS_ERROR_NOT_AVAILABLE);

  return CallQueryInterface(common, aCommonAncestor);
}

template <typename Node, typename GetParentFunc>
static Node*
GetCommonAncestorInternal(Node* aNode1,
                          Node* aNode2,
                          GetParentFunc aGetParentFunc)
{
  MOZ_ASSERT(aNode1 != aNode2);

  // Build the chain of parents
  AutoTArray<Node*, 30> parents1, parents2;
  do {
    parents1.AppendElement(aNode1);
    aNode1 = aGetParentFunc(aNode1);
  } while (aNode1);
  do {
    parents2.AppendElement(aNode2);
    aNode2 = aGetParentFunc(aNode2);
  } while (aNode2);

  // Find where the parent chain differs
  uint32_t pos1 = parents1.Length();
  uint32_t pos2 = parents2.Length();
  Node* parent = nullptr;
  uint32_t len;
  for (len = std::min(pos1, pos2); len > 0; --len) {
    Node* child1 = parents1.ElementAt(--pos1);
    Node* child2 = parents2.ElementAt(--pos2);
    if (child1 != child2) {
      break;
    }
    parent = child1;
  }

  return parent;
}

/* static */
nsINode*
nsContentUtils::GetCommonAncestorHelper(nsINode* aNode1, nsINode* aNode2)
{
  return GetCommonAncestorInternal(aNode1, aNode2, [](nsINode* aNode) {
    return aNode->GetParentNode();
  });
}

/* static */
nsIContent*
nsContentUtils::GetCommonFlattenedTreeAncestorHelper(nsIContent* aContent1,
                                                     nsIContent* aContent2)
{
  return GetCommonAncestorInternal(aContent1, aContent2, [](nsIContent* aContent) {
    return aContent->GetFlattenedTreeParent();
  });
}

/* static */
Element*
nsContentUtils::GetCommonFlattenedTreeAncestorForStyle(Element* aElement1,
                                                       Element* aElement2)
{
  return GetCommonAncestorInternal(aElement1, aElement2, [](Element* aElement) {
    return aElement->GetFlattenedTreeParentElementForStyle();
  });
}

/* static */
bool
nsContentUtils::PositionIsBefore(nsINode* aNode1, nsINode* aNode2)
{
  return (aNode2->CompareDocumentPosition(*aNode1) &
    (NodeBinding::DOCUMENT_POSITION_PRECEDING |
     NodeBinding::DOCUMENT_POSITION_DISCONNECTED)) ==
    NodeBinding::DOCUMENT_POSITION_PRECEDING;
}

/* static */
int32_t
nsContentUtils::ComparePoints(nsINode* aParent1, int32_t aOffset1,
                              nsINode* aParent2, int32_t aOffset2,
                              bool* aDisconnected)
{
  if (aParent1 == aParent2) {
    // XXX This is odd.  aOffset1 and/or aOffset2 may be -1, e.g., it's result
    //     of nsINode::ComputeIndexOf(), but this compares such invalid
    //     offset with valid offset.
    return aOffset1 < aOffset2 ? -1 :
           aOffset1 > aOffset2 ? 1 :
           0;
  }

  AutoTArray<nsINode*, 32> parents1, parents2;
  nsINode* node1 = aParent1;
  nsINode* node2 = aParent2;
  do {
    parents1.AppendElement(node1);
    node1 = node1->GetParentNode();
  } while (node1);
  do {
    parents2.AppendElement(node2);
    node2 = node2->GetParentNode();
  } while (node2);

  uint32_t pos1 = parents1.Length() - 1;
  uint32_t pos2 = parents2.Length() - 1;

  bool disconnected = parents1.ElementAt(pos1) != parents2.ElementAt(pos2);
  if (aDisconnected) {
    *aDisconnected = disconnected;
  }
  if (disconnected) {
    NS_ASSERTION(aDisconnected, "unexpected disconnected nodes");
    return 1;
  }

  // Find where the parent chains differ
  nsINode* parent = parents1.ElementAt(pos1);
  uint32_t len;
  for (len = std::min(pos1, pos2); len > 0; --len) {
    nsINode* child1 = parents1.ElementAt(--pos1);
    nsINode* child2 = parents2.ElementAt(--pos2);
    if (child1 != child2) {
      return parent->ComputeIndexOf(child1) < parent->ComputeIndexOf(child2) ? -1 : 1;
    }
    parent = child1;
  }


  // The parent chains never differed, so one of the nodes is an ancestor of
  // the other

  NS_ASSERTION(!pos1 || !pos2,
               "should have run out of parent chain for one of the nodes");

  if (!pos1) {
    nsINode* child2 = parents2.ElementAt(--pos2);
    // XXX aOffset1 may be -1 as mentioned above.  So, why does this return
    //     it's *before* of the valid DOM point?
    return aOffset1 <= parent->ComputeIndexOf(child2) ? -1 : 1;
  }

  nsINode* child1 = parents1.ElementAt(--pos1);
  // XXX aOffset2 may be -1 as mentioned above.  So, why does this return it's
  //     *after* of the valid DOM point?
  return parent->ComputeIndexOf(child1) < aOffset2 ? -1 : 1;
}

/* static */
int32_t
nsContentUtils::ComparePoints(nsIDOMNode* aParent1, int32_t aOffset1,
                              nsIDOMNode* aParent2, int32_t aOffset2,
                              bool* aDisconnected)
{
  nsCOMPtr<nsINode> parent1 = do_QueryInterface(aParent1);
  nsCOMPtr<nsINode> parent2 = do_QueryInterface(aParent2);
  NS_ENSURE_TRUE(parent1 && parent2, -1);
  return ComparePoints(parent1, aOffset1, parent2, aOffset2);
}

/* static */
int32_t
nsContentUtils::ComparePoints(const RawRangeBoundary& aFirst,
                              const RawRangeBoundary& aSecond,
                              bool* aDisconnected)
{
  if (NS_WARN_IF(!aFirst.IsSet()) || NS_WARN_IF(!aSecond.IsSet())) {
    return -1;
  }
  return ComparePoints(aFirst.Container(), aFirst.Offset(),
                       aSecond.Container(), aSecond.Offset(),
                       aDisconnected);
}

inline bool
IsCharInSet(const char* aSet,
            const char16_t aChar)
{
  char16_t ch;
  while ((ch = *aSet)) {
    if (aChar == char16_t(ch)) {
      return true;
    }
    ++aSet;
  }
  return false;
}

/**
 * This method strips leading/trailing chars, in given set, from string.
 */

// static
const nsDependentSubstring
nsContentUtils::TrimCharsInSet(const char* aSet,
                               const nsAString& aValue)
{
  nsAString::const_iterator valueCurrent, valueEnd;

  aValue.BeginReading(valueCurrent);
  aValue.EndReading(valueEnd);

  // Skip characters in the beginning
  while (valueCurrent != valueEnd) {
    if (!IsCharInSet(aSet, *valueCurrent)) {
      break;
    }
    ++valueCurrent;
  }

  if (valueCurrent != valueEnd) {
    for (;;) {
      --valueEnd;
      if (!IsCharInSet(aSet, *valueEnd)) {
        break;
      }
    }
    ++valueEnd; // Step beyond the last character we want in the value.
  }

  // valueEnd should point to the char after the last to copy
  return Substring(valueCurrent, valueEnd);
}

/**
 * This method strips leading and trailing whitespace from a string.
 */

// static
template<bool IsWhitespace(char16_t)>
const nsDependentSubstring
nsContentUtils::TrimWhitespace(const nsAString& aStr, bool aTrimTrailing)
{
  nsAString::const_iterator start, end;

  aStr.BeginReading(start);
  aStr.EndReading(end);

  // Skip whitespace characters in the beginning
  while (start != end && IsWhitespace(*start)) {
    ++start;
  }

  if (aTrimTrailing) {
    // Skip whitespace characters in the end.
    while (end != start) {
      --end;

      if (!IsWhitespace(*end)) {
        // Step back to the last non-whitespace character.
        ++end;

        break;
      }
    }
  }

  // Return a substring for the string w/o leading and/or trailing
  // whitespace

  return Substring(start, end);
}

// Declaring the templates we are going to use avoid linking issues without
// inlining the method. Considering there is not so much spaces checking
// methods we can consider this to be better than inlining.
template
const nsDependentSubstring
nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(const nsAString&, bool);
template
const nsDependentSubstring
nsContentUtils::TrimWhitespace<nsContentUtils::IsHTMLWhitespace>(const nsAString&, bool);
template
const nsDependentSubstring
nsContentUtils::TrimWhitespace<nsContentUtils::IsHTMLWhitespaceOrNBSP>(const nsAString&, bool);

static inline void KeyAppendSep(nsACString& aKey)
{
  if (!aKey.IsEmpty()) {
    aKey.Append('>');
  }
}

static inline void KeyAppendString(const nsAString& aString, nsACString& aKey)
{
  KeyAppendSep(aKey);

  // Could escape separator here if collisions happen.  > is not a legal char
  // for a name or type attribute, so we should be safe avoiding that extra work.

  AppendUTF16toUTF8(aString, aKey);
}

static inline void KeyAppendString(const nsACString& aString, nsACString& aKey)
{
  KeyAppendSep(aKey);

  // Could escape separator here if collisions happen.  > is not a legal char
  // for a name or type attribute, so we should be safe avoiding that extra work.

  aKey.Append(aString);
}

static inline void KeyAppendInt(int32_t aInt, nsACString& aKey)
{
  KeyAppendSep(aKey);

  aKey.Append(nsPrintfCString("%d", aInt));
}

static inline bool IsAutocompleteOff(const nsIContent* aContent)
{
  return aContent->IsElement() &&
    aContent->AsElement()->AttrValueIs(kNameSpaceID_None,
                                       nsGkAtoms::autocomplete,
                                       NS_LITERAL_STRING("off"),
                                       eIgnoreCase);
}

/*static*/ nsresult
nsContentUtils::GenerateStateKey(nsIContent* aContent,
                                 nsIDocument* aDocument,
                                 nsACString& aKey)
{
  aKey.Truncate();

  uint32_t partID = aDocument ? aDocument->GetPartID() : 0;

  // We must have content if we're not using a special state id
  NS_ENSURE_TRUE(aContent, NS_ERROR_FAILURE);

  // Don't capture state for anonymous content
  if (aContent->IsInAnonymousSubtree()) {
    return NS_OK;
  }

  if (IsAutocompleteOff(aContent)) {
    return NS_OK;
  }

  nsCOMPtr<nsIHTMLDocument> htmlDocument =
    do_QueryInterface(aContent->GetUncomposedDoc());

  KeyAppendInt(partID, aKey);  // first append a partID
  bool generatedUniqueKey = false;

  if (htmlDocument) {
    nsHTMLDocument* htmlDoc = static_cast<nsHTMLDocument*> (htmlDocument.get());
    RefPtr<nsContentList> htmlForms;
    RefPtr<nsContentList> htmlFormControls;
    htmlDoc->GetFormsAndFormControls(getter_AddRefs(htmlForms),
                                     getter_AddRefs(htmlFormControls));

    // If we have a form control and can calculate form information, use that
    // as the key - it is more reliable than just recording position in the
    // DOM.
    // XXXbz Is it, really?  We have bugs on this, I think...
    // Important to have a unique key, and tag/type/name may not be.
    //
    // If the control has a form, the format of the key is:
    // f>type>IndOfFormInDoc>IndOfControlInForm>FormName>name
    // else:
    // d>type>IndOfControlInDoc>name
    //
    // XXX We don't need to use index if name is there
    // XXXbz We don't?  Why not?  I don't follow.
    //
    nsCOMPtr<nsIFormControl> control(do_QueryInterface(aContent));
    if (control) {

      // Append the control type
      KeyAppendInt(control->ControlType(), aKey);

      // If in a form, add form name / index of form / index in form
      int32_t index = -1;
      Element *formElement = control->GetFormElement();
      if (formElement) {
        if (IsAutocompleteOff(formElement)) {
          aKey.Truncate();
          return NS_OK;
        }

        KeyAppendString(NS_LITERAL_CSTRING("f"), aKey);

        // Append the index of the form in the document
        index = htmlForms->IndexOf(formElement, false);
        if (index <= -1) {
          //
          // XXX HACK this uses some state that was dumped into the document
          // specifically to fix bug 138892.  What we are trying to do is *guess*
          // which form this control's state is found in, with the highly likely
          // guess that the highest form parsed so far is the one.
          // This code should not be on trunk, only branch.
          //
          index = htmlDocument->GetNumFormsSynchronous() - 1;
        }
        if (index > -1) {
          KeyAppendInt(index, aKey);

          // Append the index of the control in the form
          nsCOMPtr<nsIForm> form(do_QueryInterface(formElement));
          index = form->IndexOfControl(control);

          if (index > -1) {
            KeyAppendInt(index, aKey);
            generatedUniqueKey = true;
          }
        }

        // Append the form name
        nsAutoString formName;
        formElement->GetAttr(kNameSpaceID_None, nsGkAtoms::name, formName);
        KeyAppendString(formName, aKey);

      } else {

        KeyAppendString(NS_LITERAL_CSTRING("d"), aKey);

        // If not in a form, add index of control in document
        // Less desirable than indexing by form info.

        // Hash by index of control in doc (we are not in a form)
        // These are important as they are unique, and type/name may not be.

        // We have to flush sink notifications at this point to make
        // sure that htmlFormControls is up to date.
        index = htmlFormControls->IndexOf(aContent, true);
        if (index > -1) {
          KeyAppendInt(index, aKey);
          generatedUniqueKey = true;
        }
      }

      // Append the control name
      nsAutoString name;
      aContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::name, name);
      KeyAppendString(name, aKey);
    }
  }

  if (!generatedUniqueKey) {
    // Either we didn't have a form control or we aren't in an HTML document so
    // we can't figure out form info.  Append the tag name if it's an element
    // to avoid restoring state for one type of element on another type.
    if (aContent->IsElement()) {
      KeyAppendString(nsDependentAtomString(aContent->NodeInfo()->NameAtom()),
                      aKey);
    }
    else {
      // Append a character that is not "d" or "f" to disambiguate from
      // the case when we were a form control in an HTML document.
      KeyAppendString(NS_LITERAL_CSTRING("o"), aKey);
    }

    // Now start at aContent and append the indices of it and all its ancestors
    // in their containers.  That should at least pin down its position in the
    // DOM...
    nsINode* parent = aContent->GetParentNode();
    nsINode* content = aContent;
    while (parent) {
      KeyAppendInt(parent->ComputeIndexOf(content), aKey);
      content = parent;
      parent = content->GetParentNode();
    }
  }

  return NS_OK;
}

// static
nsIPrincipal*
nsContentUtils::SubjectPrincipal(JSContext* aCx)
{
  MOZ_ASSERT(NS_IsMainThread());

  // As opposed to SubjectPrincipal(), we do in fact assume that
  // we're in a compartment here; anyone who calls this function
  // in situations where that's not the case is doing it wrong.
  JSCompartment* compartment = js::GetContextCompartment(aCx);
  MOZ_ASSERT(compartment);

  JSPrincipals* principals = JS_GetCompartmentPrincipals(compartment);
  return nsJSPrincipals::get(principals);
}

// static
nsIPrincipal*
nsContentUtils::SubjectPrincipal()
{
  MOZ_ASSERT(IsInitialized());
  MOZ_ASSERT(NS_IsMainThread());
  JSContext* cx = GetCurrentJSContext();
  if (!cx) {
    MOZ_CRASH("Accessing the Subject Principal without an AutoJSAPI on the stack is forbidden");
  }

  JSCompartment *compartment = js::GetContextCompartment(cx);

  // When an AutoJSAPI is instantiated, we are in a null compartment until the
  // first JSAutoCompartment, which is kind of a purgatory as far as permissions
  // go. It would be nice to just hard-abort if somebody does a security check
  // in this purgatory zone, but that would be too fragile, since it could be
  // triggered by random IsCallerChrome() checks 20-levels deep.
  //
  // So we want to return _something_ here - and definitely not the System
  // Principal, since that would make an AutoJSAPI a very dangerous thing to
  // instantiate.
  //
  // The natural thing to return is a null principal. Ideally, we'd return a
  // different null principal each time, to avoid any unexpected interactions
  // when the principal accidentally gets inherited somewhere. But
  // SubjectPrincipal doesn't return strong references, so there's no way to
  // sanely manage the lifetime of multiple null principals.
  //
  // So we use a singleton null principal. To avoid it being accidentally
  // inherited and becoming a "real" subject or object principal, we do a
  // release-mode assert during compartment creation against using this
  // principal on an actual global.
  if (!compartment) {
    return sNullSubjectPrincipal;
  }

  return SubjectPrincipal(cx);
}

// static
nsIPrincipal*
nsContentUtils::ObjectPrincipal(JSObject* aObj)
{
  MOZ_ASSERT(NS_IsMainThread());

#ifdef DEBUG
  JS::AssertObjectBelongsToCurrentThread(aObj);
#endif

  // This is duplicated from nsScriptSecurityManager. We don't call through there
  // because the API unnecessarily requires a JSContext for historical reasons.
  JSCompartment *compartment = js::GetObjectCompartment(aObj);
  JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
  return nsJSPrincipals::get(principals);
}

// static
nsresult
nsContentUtils::NewURIWithDocumentCharset(nsIURI** aResult,
                                          const nsAString& aSpec,
                                          nsIDocument* aDocument,
                                          nsIURI* aBaseURI)
{
  if (aDocument) {
    return NS_NewURI(aResult, aSpec,
                     aDocument->GetDocumentCharacterSet(),
                     aBaseURI, sIOService);
  }
  return NS_NewURI(aResult, aSpec, nullptr, aBaseURI, sIOService);
}

// static
bool
nsContentUtils::IsCustomElementName(nsAtom* aName, uint32_t aNameSpaceID)
{
  // Allow non-dashed names in XUL for XBL to Custom Element migrations.
  if (aNameSpaceID == kNameSpaceID_XUL) {
    return true;
  }

  // A valid custom element name is a sequence of characters name which
  // must match the PotentialCustomElementName production:
  // PotentialCustomElementName ::= [a-z] (PCENChar)* '-' (PCENChar)*
  const char16_t* name = aName->GetUTF16String();
  uint32_t len = aName->GetLength();
  bool hasDash = false;

  if (!len || name[0] < 'a' || name[0] > 'z') {
    return false;
  }

  uint32_t i = 1;
  while (i < len) {
    if (NS_IS_HIGH_SURROGATE(name[i]) && i + 1 < len &&
        NS_IS_LOW_SURROGATE(name[i + 1])) {
      // Merged two 16-bit surrogate pairs into code point.
      char32_t code = SURROGATE_TO_UCS4(name[i], name[i + 1]);

      if (code < 0x10000 || code > 0xEFFFF) {
        return false;
      }

      i += 2;
    } else {
      if (name[i] == '-') {
        hasDash = true;
      }

      if (name[i] != '-' && name[i] != '.' &&
          name[i] != '_' && name[i] != 0xB7 &&
         (name[i] < '0' || name[i] > '9') &&
         (name[i] < 'a' || name[i] > 'z') &&
         (name[i] < 0xC0 || name[i] > 0xD6) &&
         (name[i] < 0xF8 || name[i] > 0x37D) &&
         (name[i] < 0x37F || name[i] > 0x1FFF) &&
         (name[i] < 0x200C || name[i] > 0x200D) &&
         (name[i] < 0x203F || name[i] > 0x2040) &&
         (name[i] < 0x2070 || name[i] > 0x218F) &&
         (name[i] < 0x2C00 || name[i] > 0x2FEF) &&
         (name[i] < 0x3001 || name[i] > 0xD7FF) &&
         (name[i] < 0xF900 || name[i] > 0xFDCF) &&
         (name[i] < 0xFDF0 || name[i] > 0xFFFD)) {
        return false;
      }

      i++;
    }
  }

  if (!hasDash) {
    return false;
  }

  // The custom element name must not be one of the following values:
  //  annotation-xml
  //  color-profile
  //  font-face
  //  font-face-src
  //  font-face-uri
  //  font-face-format
  //  font-face-name
  //  missing-glyph
  return aName != nsGkAtoms::annotation_xml_ &&
         aName != nsGkAtoms::colorProfile &&
         aName != nsGkAtoms::font_face &&
         aName != nsGkAtoms::font_face_src &&
         aName != nsGkAtoms::font_face_uri &&
         aName != nsGkAtoms::font_face_format &&
         aName != nsGkAtoms::font_face_name &&
         aName != nsGkAtoms::missingGlyph;
}

// static
nsresult
nsContentUtils::CheckQName(const nsAString& aQualifiedName,
                           bool aNamespaceAware,
                           const char16_t** aColon)
{
  const char* colon = nullptr;
  const char16_t* begin = aQualifiedName.BeginReading();
  const char16_t* end = aQualifiedName.EndReading();

  int result = MOZ_XMLCheckQName(reinterpret_cast<const char*>(begin),
                                 reinterpret_cast<const char*>(end),
                                 aNamespaceAware, &colon);

  if (!result) {
    if (aColon) {
      *aColon = reinterpret_cast<const char16_t*>(colon);
    }

    return NS_OK;
  }

  return NS_ERROR_DOM_INVALID_CHARACTER_ERR;
}

//static
nsresult
nsContentUtils::SplitQName(const nsIContent* aNamespaceResolver,
                           const nsString& aQName,
                           int32_t *aNamespace, nsAtom **aLocalName)
{
  const char16_t* colon;
  nsresult rv = nsContentUtils::CheckQName(aQName, true, &colon);
  NS_ENSURE_SUCCESS(rv, rv);

  if (colon) {
    const char16_t* end;
    aQName.EndReading(end);
    nsAutoString nameSpace;
    rv = aNamespaceResolver->LookupNamespaceURIInternal(Substring(aQName.get(),
                                                                  colon),
                                                        nameSpace);
    NS_ENSURE_SUCCESS(rv, rv);

    *aNamespace = NameSpaceManager()->GetNameSpaceID(nameSpace,
                                                     nsContentUtils::IsChromeDoc(aNamespaceResolver->OwnerDoc()));
    if (*aNamespace == kNameSpaceID_Unknown)
      return NS_ERROR_FAILURE;

    *aLocalName = NS_AtomizeMainThread(Substring(colon + 1, end)).take();
  }
  else {
    *aNamespace = kNameSpaceID_None;
    *aLocalName = NS_AtomizeMainThread(aQName).take();
  }
  NS_ENSURE_TRUE(aLocalName, NS_ERROR_OUT_OF_MEMORY);
  return NS_OK;
}

// static
nsresult
nsContentUtils::GetNodeInfoFromQName(const nsAString& aNamespaceURI,
                                     const nsAString& aQualifiedName,
                                     nsNodeInfoManager* aNodeInfoManager,
                                     uint16_t aNodeType,
                                     mozilla::dom::NodeInfo** aNodeInfo)
{
  const nsString& qName = PromiseFlatString(aQualifiedName);
  const char16_t* colon;
  nsresult rv = nsContentUtils::CheckQName(qName, true, &colon);
  NS_ENSURE_SUCCESS(rv, rv);

  int32_t nsID;
  sNameSpaceManager->RegisterNameSpace(aNamespaceURI, nsID);
  if (colon) {
    const char16_t* end;
    qName.EndReading(end);

    RefPtr<nsAtom> prefix =
      NS_AtomizeMainThread(Substring(qName.get(), colon));

    rv = aNodeInfoManager->GetNodeInfo(Substring(colon + 1, end), prefix,
                                       nsID, aNodeType, aNodeInfo);
  }
  else {
    rv = aNodeInfoManager->GetNodeInfo(aQualifiedName, nullptr, nsID,
                                       aNodeType, aNodeInfo);
  }
  NS_ENSURE_SUCCESS(rv, rv);

  return nsContentUtils::IsValidNodeName((*aNodeInfo)->NameAtom(),
                                         (*aNodeInfo)->GetPrefixAtom(),
                                         (*aNodeInfo)->NamespaceID()) ?
         NS_OK : NS_ERROR_DOM_NAMESPACE_ERR;
}

// static
void
nsContentUtils::SplitExpatName(const char16_t *aExpatName, nsAtom **aPrefix,
                               nsAtom **aLocalName, int32_t* aNameSpaceID)
{
  /**
   *  Expat can send the following:
   *    localName
   *    namespaceURI<separator>localName
   *    namespaceURI<separator>localName<separator>prefix
   *
   *  and we use 0xFFFF for the <separator>.
   *
   */

  const char16_t *uriEnd = nullptr;
  const char16_t *nameEnd = nullptr;
  const char16_t *pos;
  for (pos = aExpatName; *pos; ++pos) {
    if (*pos == 0xFFFF) {
      if (uriEnd) {
        nameEnd = pos;
      }
      else {
        uriEnd = pos;
      }
    }
  }

  const char16_t *nameStart;
  if (uriEnd) {
    if (sNameSpaceManager) {
      sNameSpaceManager->RegisterNameSpace(nsDependentSubstring(aExpatName,
                                                                uriEnd),
                                           *aNameSpaceID);
    }
    else {
      *aNameSpaceID = kNameSpaceID_Unknown;
    }

    nameStart = (uriEnd + 1);
    if (nameEnd)  {
      const char16_t *prefixStart = nameEnd + 1;
      *aPrefix = NS_AtomizeMainThread(Substring(prefixStart, pos)).take();
    }
    else {
      nameEnd = pos;
      *aPrefix = nullptr;
    }
  }
  else {
    *aNameSpaceID = kNameSpaceID_None;
    nameStart = aExpatName;
    nameEnd = pos;
    *aPrefix = nullptr;
  }
  *aLocalName = NS_AtomizeMainThread(Substring(nameStart, nameEnd)).take();
}

// static
nsIPresShell*
nsContentUtils::GetPresShellForContent(const nsIContent* aContent)
{
  nsIDocument* doc = aContent->GetComposedDoc();
  if (!doc) {
    return nullptr;
  }

  return doc->GetShell();
}

// static
nsPresContext*
nsContentUtils::GetContextForContent(const nsIContent* aContent)
{
  nsIPresShell* presShell = GetPresShellForContent(aContent);

  if (!presShell) {
    return nullptr;
  }

  return presShell->GetPresContext();
}

// static
bool
nsContentUtils::CanLoadImage(nsIURI* aURI, nsINode* aNode,
                             nsIDocument* aLoadingDocument,
                             nsIPrincipal* aLoadingPrincipal,
                             int16_t* aImageBlockingStatus,
                             uint32_t aContentType)
{
  NS_PRECONDITION(aURI, "Must have a URI");
  NS_PRECONDITION(aLoadingDocument, "Must have a document");
  NS_PRECONDITION(aLoadingPrincipal, "Must have a loading principal");

  nsresult rv;

  uint32_t appType = nsIDocShell::APP_TYPE_UNKNOWN;

  {
    nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aLoadingDocument->GetDocShell();
    if (docShellTreeItem) {
      nsCOMPtr<nsIDocShellTreeItem> root;
      docShellTreeItem->GetRootTreeItem(getter_AddRefs(root));

      nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(root));

      if (!docShell || NS_FAILED(docShell->GetAppType(&appType))) {
        appType = nsIDocShell::APP_TYPE_UNKNOWN;
      }
    }
  }

  if (appType != nsIDocShell::APP_TYPE_EDITOR) {
    // Editor apps get special treatment here, editors can load images
    // from anywhere.  This allows editor to insert images from file://
    // into documents that are being edited.
    rv = sSecurityManager->
      CheckLoadURIWithPrincipal(aLoadingPrincipal, aURI,
                                nsIScriptSecurityManager::ALLOW_CHROME);
    if (NS_FAILED(rv)) {
      if (aImageBlockingStatus) {
        // Reject the request itself, not all requests to the relevant
        // server...
        *aImageBlockingStatus = nsIContentPolicy::REJECT_REQUEST;
      }
      return false;
    }
  }

  nsCOMPtr<nsILoadInfo> secCheckLoadInfo =
    new LoadInfo(aLoadingPrincipal,
                 aLoadingPrincipal, // triggering principal
                 aNode,
                 nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK,
                 aContentType);

  int16_t decision = nsIContentPolicy::ACCEPT;

  rv = NS_CheckContentLoadPolicy(aURI, secCheckLoadInfo,
                                 EmptyCString(), //mime guess
                                 &decision,
                                 GetContentPolicy());

  if (aImageBlockingStatus) {
    *aImageBlockingStatus =
      NS_FAILED(rv) ? nsIContentPolicy::REJECT_REQUEST : decision;
  }
  return NS_FAILED(rv) ? false : NS_CP_ACCEPTED(decision);
}

// static
mozilla::OriginAttributes
nsContentUtils::GetOriginAttributes(nsIDocument* aDocument)
{
  if (!aDocument) {
    return mozilla::OriginAttributes();
  }

  nsCOMPtr<nsILoadGroup> loadGroup = aDocument->GetDocumentLoadGroup();
  if (loadGroup) {
    return GetOriginAttributes(loadGroup);
  }

  mozilla::OriginAttributes attrs;
  nsCOMPtr<nsIChannel> channel = aDocument->GetChannel();
  if (channel) {
    NS_GetOriginAttributes(channel, attrs);
  }
  return attrs;
}

// static
mozilla::OriginAttributes
nsContentUtils::GetOriginAttributes(nsILoadGroup* aLoadGroup)
{
  if (!aLoadGroup) {
    return mozilla::OriginAttributes();
  }
  mozilla::OriginAttributes attrs;
  nsCOMPtr<nsIInterfaceRequestor> callbacks;
  aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
  if (callbacks) {
    nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
    if (loadContext) {
      loadContext->GetOriginAttributes(attrs);
    }
  }
  return attrs;
}

// static
bool
nsContentUtils::IsInPrivateBrowsing(nsIDocument* aDoc)
{
  if (!aDoc) {
    return false;
  }

  nsCOMPtr<nsILoadGroup> loadGroup = aDoc->GetDocumentLoadGroup();
  if (loadGroup) {
    nsCOMPtr<nsIInterfaceRequestor> callbacks;
    loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
    if (callbacks) {
      nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
      if (loadContext) {
        return loadContext->UsePrivateBrowsing();
      }
    }
  }

  nsCOMPtr<nsIChannel> channel = aDoc->GetChannel();
  return channel && NS_UsePrivateBrowsing(channel);
}

// static
bool
nsContentUtils::IsInPrivateBrowsing(nsILoadGroup* aLoadGroup)
{
  if (!aLoadGroup) {
    return false;
  }
  bool isPrivate = false;
  nsCOMPtr<nsIInterfaceRequestor> callbacks;
  aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
  if (callbacks) {
    nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(callbacks);
    isPrivate = loadContext && loadContext->UsePrivateBrowsing();
  }
  return isPrivate;
}

bool
nsContentUtils::DocumentInactiveForImageLoads(nsIDocument* aDocument)
{
  if (aDocument && !IsChromeDoc(aDocument) && !aDocument->IsResourceDoc()) {
    nsCOMPtr<nsPIDOMWindowInner> win =
      do_QueryInterface(aDocument->GetScopeObject());
    return !win || !win->GetDocShell();
  }
  return false;
}

imgLoader*
nsContentUtils::GetImgLoaderForDocument(nsIDocument* aDoc)
{
  NS_ENSURE_TRUE(!DocumentInactiveForImageLoads(aDoc), nullptr);

  if (!aDoc) {
    return imgLoader::NormalLoader();
  }
  bool isPrivate = IsInPrivateBrowsing(aDoc);
  return isPrivate ? imgLoader::PrivateBrowsingLoader()
                   : imgLoader::NormalLoader();
}

// static
imgLoader*
nsContentUtils::GetImgLoaderForChannel(nsIChannel* aChannel,
                                       nsIDocument* aContext)
{
  NS_ENSURE_TRUE(!DocumentInactiveForImageLoads(aContext), nullptr);

  if (!aChannel) {
    return imgLoader::NormalLoader();
  }
  nsCOMPtr<nsILoadContext> context;
  NS_QueryNotificationCallbacks(aChannel, context);
  return context && context->UsePrivateBrowsing() ?
                      imgLoader::PrivateBrowsingLoader() :
                      imgLoader::NormalLoader();
}

// static
bool
nsContentUtils::IsImageInCache(nsIURI* aURI, nsIDocument* aDocument)
{
    imgILoader* loader = GetImgLoaderForDocument(aDocument);
    nsCOMPtr<imgICache> cache = do_QueryInterface(loader);

    // If something unexpected happened we return false, otherwise if props
    // is set, the image is cached and we return true
    nsCOMPtr<nsIProperties> props;
    nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(aDocument);
    nsresult rv = cache->FindEntryProperties(aURI, domDoc, getter_AddRefs(props));
    return (NS_SUCCEEDED(rv) && props);
}

// static
int32_t
nsContentUtils::CORSModeToLoadImageFlags(mozilla::CORSMode aMode)
{
  switch (aMode) {
  case CORS_ANONYMOUS:
    return imgILoader::LOAD_CORS_ANONYMOUS;
  case CORS_USE_CREDENTIALS:
    return imgILoader::LOAD_CORS_USE_CREDENTIALS;
  default:
    return 0;
  }
}

// static
nsresult
nsContentUtils::LoadImage(nsIURI* aURI, nsINode* aContext,
                          nsIDocument* aLoadingDocument,
                          nsIPrincipal* aLoadingPrincipal,
                          uint64_t aRequestContextID,
                          nsIURI* aReferrer,
                          net::ReferrerPolicy aReferrerPolicy,
                          imgINotificationObserver* aObserver, int32_t aLoadFlags,
                          const nsAString& initiatorType,
                          imgRequestProxy** aRequest,
                          uint32_t aContentPolicyType,
                          bool aUseUrgentStartForChannel)
{
  NS_PRECONDITION(aURI, "Must have a URI");
  NS_PRECONDITION(aContext, "Must have a context");
  NS_PRECONDITION(aLoadingDocument, "Must have a document");
  NS_PRECONDITION(aLoadingPrincipal, "Must have a principal");
  NS_PRECONDITION(aRequest, "Null out param");

  imgLoader* imgLoader = GetImgLoaderForDocument(aLoadingDocument);
  if (!imgLoader) {
    // nothing we can do here
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsILoadGroup> loadGroup = aLoadingDocument->GetDocumentLoadGroup();

  nsIURI *documentURI = aLoadingDocument->GetDocumentURI();

  NS_ASSERTION(loadGroup || IsFontTableURI(documentURI),
               "Could not get loadgroup; onload may fire too early");

  // Make the URI immutable so people won't change it under us
  NS_TryToSetImmutable(aURI);

  // XXXbz using "documentURI" for the initialDocumentURI is not quite
  // right, but the best we can do here...
  return imgLoader->LoadImage(aURI,                 /* uri to load */
                              documentURI,          /* initialDocumentURI */
                              aReferrer,            /* referrer */
                              aReferrerPolicy,      /* referrer policy */
                              aLoadingPrincipal,    /* loading principal */
                              aRequestContextID,    /* request context ID */
                              loadGroup,            /* loadgroup */
                              aObserver,            /* imgINotificationObserver */
                              aContext,             /* loading context */
                              aLoadingDocument,     /* uniquification key */
                              aLoadFlags,           /* load flags */
                              nullptr,              /* cache key */
                              aContentPolicyType,   /* content policy type */
                              initiatorType,        /* the load initiator */
                              aUseUrgentStartForChannel, /* urgent-start flag */
                              aRequest);
}

// static
already_AddRefed<imgIContainer>
nsContentUtils::GetImageFromContent(nsIImageLoadingContent* aContent,
                                    imgIRequest **aRequest)
{
  if (aRequest) {
    *aRequest = nullptr;
  }

  NS_ENSURE_TRUE(aContent, nullptr);

  nsCOMPtr<imgIRequest> imgRequest;
  aContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
                      getter_AddRefs(imgRequest));
  if (!imgRequest) {
    return nullptr;
  }

  nsCOMPtr<imgIContainer> imgContainer;
  imgRequest->GetImage(getter_AddRefs(imgContainer));

  if (!imgContainer) {
    return nullptr;
  }

  if (aRequest) {
    imgRequest.swap(*aRequest);
  }

  return imgContainer.forget();
}

//static
already_AddRefed<imgRequestProxy>
nsContentUtils::GetStaticRequest(nsIDocument* aLoadingDocument,
                                 imgRequestProxy* aRequest)
{
  NS_ENSURE_TRUE(aRequest, nullptr);
  RefPtr<imgRequestProxy> retval;
  aRequest->GetStaticRequest(aLoadingDocument, getter_AddRefs(retval));
  return retval.forget();
}

// static
bool
nsContentUtils::ContentIsDraggable(nsIContent* aContent)
{
  MOZ_ASSERT(aContent);

  if (auto htmlElement = nsGenericHTMLElement::FromNode(aContent)) {
    if (htmlElement->Draggable()) {
      return true;
    }

    if (htmlElement->AttrValueIs(kNameSpaceID_None,
                                 nsGkAtoms::draggable,
                                 nsGkAtoms::_false,
                                 eIgnoreCase)) {
      return false;
    }
  }

  // special handling for content area image and link dragging
  return IsDraggableImage(aContent) || IsDraggableLink(aContent);
}

// static
bool
nsContentUtils::IsDraggableImage(nsIContent* aContent)
{
  NS_PRECONDITION(aContent, "Must have content node to test");

  nsCOMPtr<nsIImageLoadingContent> imageContent(do_QueryInterface(aContent));
  if (!imageContent) {
    return false;
  }

  nsCOMPtr<imgIRequest> imgRequest;
  imageContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
                           getter_AddRefs(imgRequest));

  // XXXbz It may be draggable even if the request resulted in an error.  Why?
  // Not sure; that's what the old nsContentAreaDragDrop/nsFrame code did.
  return imgRequest != nullptr;
}

// static
bool
nsContentUtils::IsDraggableLink(const nsIContent* aContent) {
  nsCOMPtr<nsIURI> absURI;
  return aContent->IsLink(getter_AddRefs(absURI));
}

// static
nsresult
nsContentUtils::QNameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsAtom* aName,
                             mozilla::dom::NodeInfo** aResult)
{
  nsNodeInfoManager *niMgr = aNodeInfo->NodeInfoManager();

  *aResult = niMgr->GetNodeInfo(aName, nullptr,
                                aNodeInfo->NamespaceID(),
                                aNodeInfo->NodeType(),
                                aNodeInfo->GetExtraName()).take();
  return NS_OK;
}


static bool
TestSitePerm(nsIPrincipal* aPrincipal, const char* aType, uint32_t aPerm, bool aExactHostMatch)
{
  if (!aPrincipal) {
    // We always deny (i.e. don't allow) the permission if we don't have a
    // principal.
    return aPerm != nsIPermissionManager::ALLOW_ACTION;
  }

  nsCOMPtr<nsIPermissionManager> permMgr = services::GetPermissionManager();
  NS_ENSURE_TRUE(permMgr, false);

  uint32_t perm;
  nsresult rv;
  if (aExactHostMatch) {
    rv = permMgr->TestExactPermissionFromPrincipal(aPrincipal, aType, &perm);
  } else {
    rv = permMgr->TestPermissionFromPrincipal(aPrincipal, aType, &perm);
  }
  NS_ENSURE_SUCCESS(rv, false);

  return perm == aPerm;
}

bool
nsContentUtils::IsSitePermAllow(nsIPrincipal* aPrincipal, const char* aType)
{
  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::ALLOW_ACTION, false);
}

bool
nsContentUtils::IsSitePermDeny(nsIPrincipal* aPrincipal, const char* aType)
{
  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::DENY_ACTION, false);
}

bool
nsContentUtils::IsExactSitePermAllow(nsIPrincipal* aPrincipal, const char* aType)
{
  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::ALLOW_ACTION, true);
}

bool
nsContentUtils::IsExactSitePermDeny(nsIPrincipal* aPrincipal, const char* aType)
{
  return TestSitePerm(aPrincipal, aType, nsIPermissionManager::DENY_ACTION, true);
}

static const char *gEventNames[] = {"event"};
static const char *gSVGEventNames[] = {"evt"};
// for b/w compat, the first name to onerror is still 'event', even though it
// is actually the error message
static const char *gOnErrorNames[] = {"event", "source", "lineno",
                                      "colno", "error"};

// static
void
nsContentUtils::GetEventArgNames(int32_t aNameSpaceID,
                                 nsAtom *aEventName,
                                 bool aIsForWindow,
                                 uint32_t *aArgCount,
                                 const char*** aArgArray)
{
#define SET_EVENT_ARG_NAMES(names) \
    *aArgCount = sizeof(names)/sizeof(names[0]); \
    *aArgArray = names;

  // JSEventHandler is what does the arg magic for onerror, and it does
  // not seem to take the namespace into account.  So we let onerror in all
  // namespaces get the 3 arg names.
  if (aEventName == nsGkAtoms::onerror && aIsForWindow) {
    SET_EVENT_ARG_NAMES(gOnErrorNames);
  } else if (aNameSpaceID == kNameSpaceID_SVG) {
    SET_EVENT_ARG_NAMES(gSVGEventNames);
  } else {
    SET_EVENT_ARG_NAMES(gEventNames);
  }
}

static const char gPropertiesFiles[nsContentUtils::PropertiesFile_COUNT][56] = {
  // Must line up with the enum values in |PropertiesFile| enum.
  "chrome://global/locale/css.properties",
  "chrome://global/locale/xbl.properties",
  "chrome://global/locale/xul.properties",
  "chrome://global/locale/layout_errors.properties",
  "chrome://global/locale/layout/HtmlForm.properties",
  "chrome://global/locale/printing.properties",
  "chrome://global/locale/dom/dom.properties",
  "chrome://global/locale/layout/htmlparser.properties",
  "chrome://global/locale/svg/svg.properties",
  "chrome://branding/locale/brand.properties",
  "chrome://global/locale/commonDialogs.properties",
  "chrome://global/locale/mathml/mathml.properties",
  "chrome://global/locale/security/security.properties",
  "chrome://necko/locale/necko.properties"
};

/* static */ nsresult
nsContentUtils::EnsureStringBundle(PropertiesFile aFile)
{
  if (!sStringBundles[aFile]) {
    if (!sStringBundleService) {
      nsresult rv =
        CallGetService(NS_STRINGBUNDLE_CONTRACTID, &sStringBundleService);
      NS_ENSURE_SUCCESS(rv, rv);
    }
    nsIStringBundle *bundle;
    nsresult rv =
      sStringBundleService->CreateBundle(gPropertiesFiles[aFile], &bundle);
    NS_ENSURE_SUCCESS(rv, rv);
    sStringBundles[aFile] = bundle; // transfer ownership
  }
  return NS_OK;
}

/* static */
void
nsContentUtils::AsyncPrecreateStringBundles()
{
  for (uint32_t bundleIndex = 0; bundleIndex < PropertiesFile_COUNT; ++bundleIndex) {
    nsresult rv = NS_IdleDispatchToCurrentThread(
      NS_NewRunnableFunction("AsyncPrecreateStringBundles",
                             [bundleIndex]() {
                               PropertiesFile file = static_cast<PropertiesFile>(bundleIndex);
                               EnsureStringBundle(file);
                               nsIStringBundle *bundle = sStringBundles[file];
                               bundle->AsyncPreload();
                             }));
    Unused << NS_WARN_IF(NS_FAILED(rv));
  }
}

/* static */
nsresult nsContentUtils::GetLocalizedString(PropertiesFile aFile,
                                            const char* aKey,
                                            nsAString& aResult)
{
  nsresult rv = EnsureStringBundle(aFile);
  NS_ENSURE_SUCCESS(rv, rv);
  nsIStringBundle *bundle = sStringBundles[aFile];
  return bundle->GetStringFromName(aKey, aResult);
}

/* static */
nsresult nsContentUtils::FormatLocalizedString(PropertiesFile aFile,
                                               const char* aKey,
                                               const char16_t **aParams,
                                               uint32_t aParamsLength,
                                               nsAString& aResult)
{
  nsresult rv = EnsureStringBundle(aFile);
  NS_ENSURE_SUCCESS(rv, rv);
  nsIStringBundle *bundle = sStringBundles[aFile];

  if (!aParams || !aParamsLength) {
    return bundle->GetStringFromName(aKey, aResult);
  }

  return bundle->FormatStringFromName(aKey, aParams, aParamsLength, aResult);
}

/* static */
nsresult nsContentUtils::FormatLocalizedString(
                                          PropertiesFile aFile,
                                          const char* aKey,
                                          const nsTArray<nsString>& aParamArray,
                                          nsAString& aResult)
{
  MOZ_ASSERT(NS_IsMainThread());

  UniquePtr<const char16_t*[]> params;
  uint32_t paramsLength = aParamArray.Length();
  if (paramsLength > 0) {
    params = MakeUnique<const char16_t*[]>(paramsLength);
    for (uint32_t i = 0; i < paramsLength; ++i) {
      params[i] = aParamArray[i].get();
    }
  }
  return FormatLocalizedString(aFile, aKey, params.get(), paramsLength,
                               aResult);
}


/* static */ void
nsContentUtils::LogSimpleConsoleError(const nsAString& aErrorText,
                                      const char * classification,
                                      bool aFromPrivateWindow)
{
  nsCOMPtr<nsIScriptError> scriptError =
    do_CreateInstance(NS_SCRIPTERROR_CONTRACTID);
  if (scriptError) {
    nsCOMPtr<nsIConsoleService> console =
      do_GetService(NS_CONSOLESERVICE_CONTRACTID);
    if (console && NS_SUCCEEDED(scriptError->Init(aErrorText, EmptyString(),
                                                  EmptyString(), 0, 0,
                                                  nsIScriptError::errorFlag,
                                                  classification,
                                                  aFromPrivateWindow))) {
      console->LogMessage(scriptError);
    }
  }
}

/* static */ nsresult
nsContentUtils::ReportToConsole(uint32_t aErrorFlags,
                                const nsACString& aCategory,
                                const nsIDocument* aDocument,
                                PropertiesFile aFile,
                                const char *aMessageName,
                                const char16_t **aParams,
                                uint32_t aParamsLength,
                                nsIURI* aURI,
                                const nsString& aSourceLine,
                                uint32_t aLineNumber,
                                uint32_t aColumnNumber)
{
  NS_ASSERTION((aParams && aParamsLength) || (!aParams && !aParamsLength),
               "Supply either both parameters and their number or no"
               "parameters and 0.");

  nsresult rv;
  nsAutoString errorText;
  if (aParams) {
    rv = FormatLocalizedString(aFile, aMessageName, aParams, aParamsLength,
                               errorText);
  }
  else {
    rv = GetLocalizedString(aFile, aMessageName, errorText);
  }
  NS_ENSURE_SUCCESS(rv, rv);

  return ReportToConsoleNonLocalized(errorText, aErrorFlags, aCategory,
                                     aDocument, aURI, aSourceLine,
                                     aLineNumber, aColumnNumber);
}

/* static */ void
nsContentUtils::ReportEmptyGetElementByIdArg(const nsIDocument* aDoc)
{
  ReportToConsole(nsIScriptError::warningFlag,
                  NS_LITERAL_CSTRING("DOM"), aDoc,
                  nsContentUtils::eDOM_PROPERTIES,
                  "EmptyGetElementByIdParam");
}

/* static */ nsresult
nsContentUtils::ReportToConsoleNonLocalized(const nsAString& aErrorText,
                                            uint32_t aErrorFlags,
                                            const nsACString& aCategory,
                                            const nsIDocument* aDocument,
                                            nsIURI* aURI,
                                            const nsString& aSourceLine,
                                            uint32_t aLineNumber,
                                            uint32_t aColumnNumber,
                                            MissingErrorLocationMode aLocationMode)
{
  uint64_t innerWindowID = 0;
  if (aDocument) {
    if (!aURI) {
      aURI = aDocument->GetDocumentURI();
    }
    innerWindowID = aDocument->InnerWindowID();
  }

  return ReportToConsoleByWindowID(aErrorText, aErrorFlags, aCategory,
                                   innerWindowID, aURI, aSourceLine,
                                   aLineNumber, aColumnNumber, aLocationMode);
}

/* static */ nsresult
nsContentUtils::ReportToConsoleByWindowID(const nsAString& aErrorText,
                                          uint32_t aErrorFlags,
                                          const nsACString& aCategory,
                                          uint64_t aInnerWindowID,
                                          nsIURI* aURI,
                                          const nsString& aSourceLine,
                                          uint32_t aLineNumber,
                                          uint32_t aColumnNumber,
                                          MissingErrorLocationMode aLocationMode)
{
  nsresult rv;
  if (!sConsoleService) { // only need to bother null-checking here
    rv = CallGetService(NS_CONSOLESERVICE_CONTRACTID, &sConsoleService);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsAutoCString spec;
  if (!aLineNumber && aLocationMode == eUSE_CALLING_LOCATION) {
    JSContext *cx = GetCurrentJSContext();
    if (cx) {
      nsJSUtils::GetCallingLocation(cx, spec, &aLineNumber, &aColumnNumber);
    }
  }

  nsCOMPtr<nsIScriptError> errorObject =
      do_CreateInstance(NS_SCRIPTERROR_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!spec.IsEmpty()) {
    rv = errorObject->InitWithWindowID(aErrorText,
                                       NS_ConvertUTF8toUTF16(spec), // file name
                                       aSourceLine,
                                       aLineNumber, aColumnNumber,
                                       aErrorFlags, aCategory,
                                       aInnerWindowID);
  } else {
    rv = errorObject->InitWithSourceURI(aErrorText,
                                        aURI,
                                        aSourceLine,
                                        aLineNumber, aColumnNumber,
                                        aErrorFlags, aCategory,
                                        aInnerWindowID);
  }
  NS_ENSURE_SUCCESS(rv, rv);

  return sConsoleService->LogMessage(errorObject);
}

void
nsContentUtils::LogMessageToConsole(const char* aMsg)
{
  if (!sConsoleService) { // only need to bother null-checking here
    CallGetService(NS_CONSOLESERVICE_CONTRACTID, &sConsoleService);
    if (!sConsoleService) {
      return;
    }
  }
  sConsoleService->LogStringMessage(NS_ConvertUTF8toUTF16(aMsg).get());
}

bool
nsContentUtils::IsChromeDoc(nsIDocument *aDocument)
{
  if (!aDocument) {
    return false;
  }
  return aDocument->NodePrincipal() == sSystemPrincipal;
}

bool
nsContentUtils::IsChildOfSameType(nsIDocument* aDoc)
{
  nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(aDoc->GetDocShell());
  nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
  if (docShellAsItem) {
    docShellAsItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
  }
  return sameTypeParent != nullptr;
}

bool
nsContentUtils::IsPlainTextType(const nsACString& aContentType)
{
  // NOTE: if you add a type here, add it to the CONTENTDLF_CATEGORIES
  // define in nsContentDLF.h as well.
  return aContentType.EqualsLiteral(TEXT_PLAIN) ||
         aContentType.EqualsLiteral(TEXT_CSS) ||
         aContentType.EqualsLiteral(TEXT_CACHE_MANIFEST) ||
         aContentType.EqualsLiteral(TEXT_VTT) ||
         aContentType.EqualsLiteral(APPLICATION_JAVASCRIPT) ||
         aContentType.EqualsLiteral(APPLICATION_XJAVASCRIPT) ||
         aContentType.EqualsLiteral(TEXT_ECMASCRIPT) ||
         aContentType.EqualsLiteral(APPLICATION_ECMASCRIPT) ||
         aContentType.EqualsLiteral(TEXT_JAVASCRIPT) ||
         aContentType.EqualsLiteral(APPLICATION_JSON) ||
         aContentType.EqualsLiteral(TEXT_JSON);
}

bool
nsContentUtils::IsUtf8OnlyPlainTextType(const nsACString& aContentType)
{
  // NOTE: This must be a subset of the list in IsPlainTextType().
  return aContentType.EqualsLiteral(TEXT_CACHE_MANIFEST) ||
         aContentType.EqualsLiteral(APPLICATION_JSON) ||
         aContentType.EqualsLiteral(TEXT_JSON) ||
         aContentType.EqualsLiteral(TEXT_VTT);
}

bool
nsContentUtils::GetWrapperSafeScriptFilename(nsIDocument* aDocument,
                                             nsIURI* aURI,
                                             nsACString& aScriptURI,
                                             nsresult* aRv)
{
  MOZ_ASSERT(aRv);
  bool scriptFileNameModified = false;
  *aRv = NS_OK;

  *aRv = aURI->GetSpec(aScriptURI);
  NS_ENSURE_SUCCESS(*aRv, false);

  if (IsChromeDoc(aDocument)) {
    nsCOMPtr<nsIChromeRegistry> chromeReg =
      mozilla::services::GetChromeRegistryService();

    if (!chromeReg) {
      // If we're running w/o a chrome registry we won't modify any
      // script file names.

      return scriptFileNameModified;
    }

    bool docWrappersEnabled =
      chromeReg->WrappersEnabled(aDocument->GetDocumentURI());

    bool uriWrappersEnabled = chromeReg->WrappersEnabled(aURI);

    nsIURI *docURI = aDocument->GetDocumentURI();

    if (docURI && docWrappersEnabled && !uriWrappersEnabled) {
      // aURI is a script from a URL that doesn't get wrapper
      // automation. aDocument is a chrome document that does get
      // wrapper automation. Prepend the chrome document's URI
      // followed by the string " -> " to the URI of the script we're
      // loading here so that script in that URI gets the same wrapper
      // automation that the chrome document expects.
      nsAutoCString spec;
      *aRv = docURI->GetSpec(spec);
      if (NS_WARN_IF(NS_FAILED(*aRv))) {
        return false;
      }

      spec.AppendLiteral(" -> ");
      spec.Append(aScriptURI);

      aScriptURI = spec;

      scriptFileNameModified = true;
    }
  }

  return scriptFileNameModified;
}

// static
bool
nsContentUtils::IsInChromeDocshell(nsIDocument *aDocument)
{
  if (!aDocument) {
    return false;
  }

  if (aDocument->GetDisplayDocument()) {
    return IsInChromeDocshell(aDocument->GetDisplayDocument());
  }

  nsCOMPtr<nsIDocShellTreeItem> docShell = aDocument->GetDocShell();
  if (!docShell) {
    return false;
  }

  return docShell->ItemType() == nsIDocShellTreeItem::typeChrome;
}

// static
nsIContentPolicy*
nsContentUtils::GetContentPolicy()
{
  if (!sTriedToGetContentPolicy) {
    CallGetService(NS_CONTENTPOLICY_CONTRACTID, &sContentPolicyService);
    // It's OK to not have a content policy service
    sTriedToGetContentPolicy = true;
  }

  return sContentPolicyService;
}

// static
bool
nsContentUtils::IsEventAttributeName(nsAtom* aName, int32_t aType)
{
  const char16_t* name = aName->GetUTF16String();
  if (name[0] != 'o' || name[1] != 'n')
    return false;

  EventNameMapping mapping;
  return (sAtomEventTable->Get(aName, &mapping) && mapping.mType & aType);
}

// static
EventMessage
nsContentUtils::GetEventMessage(nsAtom* aName)
{
  if (aName) {
    EventNameMapping mapping;
    if (sAtomEventTable->Get(aName, &mapping)) {
      return mapping.mMessage;
    }
  }

  return eUnidentifiedEvent;
}

// static
mozilla::EventClassID
nsContentUtils::GetEventClassID(const nsAString& aName)
{
  EventNameMapping mapping;
  if (sStringEventTable->Get(aName, &mapping))
    return mapping.mEventClassID;

  return eBasicEventClass;
}

nsAtom*
nsContentUtils::GetEventMessageAndAtom(const nsAString& aName,
                                       mozilla::EventClassID aEventClassID,
                                       EventMessage* aEventMessage)
{
  EventNameMapping mapping;
  if (sStringEventTable->Get(aName, &mapping)) {
    *aEventMessage =
      mapping.mEventClassID == aEventClassID ? mapping.mMessage :
                                               eUnidentifiedEvent;
    return mapping.mAtom;
  }

  // If we have cached lots of user defined event names, clear some of them.
  if (sUserDefinedEvents->Length() > 127) {
    while (sUserDefinedEvents->Length() > 64) {
      nsAtom* first = sUserDefinedEvents->ElementAt(0);
      sStringEventTable->Remove(Substring(nsDependentAtomString(first), 2));
      sUserDefinedEvents->RemoveElementAt(0);
    }
  }

  *aEventMessage = eUnidentifiedEvent;
  RefPtr<nsAtom> atom =
    NS_AtomizeMainThread(NS_LITERAL_STRING("on") + aName);
  sUserDefinedEvents->AppendElement(atom);
  mapping.mAtom = atom;
  mapping.mMessage = eUnidentifiedEvent;
  mapping.mType = EventNameType_None;
  mapping.mEventClassID = eBasicEventClass;
  // This is a slow hashtable call, but at least we cache the result for the
  // following calls. Because GetEventMessageAndAtomForListener utilizes
  // sStringEventTable, it needs to know in which cases sStringEventTable
  // doesn't contain the information it needs so that it can use
  // sAtomEventTable instead.
  mapping.mMaybeSpecialSVGorSMILEvent =
    GetEventMessage(atom) != eUnidentifiedEvent;
  sStringEventTable->Put(aName, mapping);
  return mapping.mAtom;
}

// static
EventMessage
nsContentUtils::GetEventMessageAndAtomForListener(const nsAString& aName,
                                                  nsAtom** aOnName)
{
  // Because of SVG/SMIL sStringEventTable contains a subset of the event names
  // comparing to the sAtomEventTable. However, usually sStringEventTable
  // contains the information we need, so in order to reduce hashtable
  // lookups, start from it.
  EventNameMapping mapping;
  EventMessage msg = eUnidentifiedEvent;
  RefPtr<nsAtom> atom;
  if (sStringEventTable->Get(aName, &mapping)) {
    if (mapping.mMaybeSpecialSVGorSMILEvent) {
      // Try the atom version so that we should get the right message for
      // SVG/SMIL.
      atom = NS_AtomizeMainThread(NS_LITERAL_STRING("on") + aName);
      msg = GetEventMessage(atom);
    } else {
      atom = mapping.mAtom;
      msg = mapping.mMessage;
    }
    atom.forget(aOnName);
    return msg;
  }

  // GetEventMessageAndAtom will cache the event type for the future usage...
  GetEventMessageAndAtom(aName, eBasicEventClass, &msg);

  // ...and then call this method recursively to get the message and atom from
  // now updated sStringEventTable.
  return GetEventMessageAndAtomForListener(aName, aOnName);
}

static
nsresult GetEventAndTarget(nsIDocument* aDoc, nsISupports* aTarget,
                           const nsAString& aEventName,
                           bool aCanBubble, bool aCancelable,
                           bool aTrusted, Event** aEvent,
                           EventTarget** aTargetOut)
{
  nsCOMPtr<EventTarget> target(do_QueryInterface(aTarget));
  NS_ENSURE_TRUE(aDoc && target, NS_ERROR_INVALID_ARG);

  ErrorResult err;
  RefPtr<Event> event = aDoc->CreateEvent(NS_LITERAL_STRING("Events"),
                                          CallerType::System, err);
  if (NS_WARN_IF(err.Failed())) {
    return err.StealNSResult();
  }

  event->InitEvent(aEventName, aCanBubble, aCancelable);
  event->SetTrusted(aTrusted);

  nsresult rv = event->SetTarget(target);
  NS_ENSURE_SUCCESS(rv, rv);

  event.forget(aEvent);
  target.forget(aTargetOut);
  return NS_OK;
}

// static
nsresult
nsContentUtils::DispatchTrustedEvent(nsIDocument* aDoc, nsISupports* aTarget,
                                     const nsAString& aEventName,
                                     bool aCanBubble, bool aCancelable,
                                     bool* aDefaultAction)
{
  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
                       true, aDefaultAction);
}

// static
nsresult
nsContentUtils::DispatchUntrustedEvent(nsIDocument* aDoc, nsISupports* aTarget,
                                       const nsAString& aEventName,
                                       bool aCanBubble, bool aCancelable,
                                       bool* aDefaultAction)
{
  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
                       false, aDefaultAction);
}

// static
nsresult
nsContentUtils::DispatchEvent(nsIDocument* aDoc, nsISupports* aTarget,
                              const nsAString& aEventName,
                              bool aCanBubble, bool aCancelable,
                              bool aTrusted, bool* aDefaultAction,
                              bool aOnlyChromeDispatch)
{
  RefPtr<Event> event;
  nsCOMPtr<EventTarget> target;
  nsresult rv = GetEventAndTarget(aDoc, aTarget, aEventName, aCanBubble,
                                  aCancelable, aTrusted, getter_AddRefs(event),
                                  getter_AddRefs(target));
  NS_ENSURE_SUCCESS(rv, rv);
  event->WidgetEventPtr()->mFlags.mOnlyChromeDispatch = aOnlyChromeDispatch;

  ErrorResult err;
  bool doDefault = target->DispatchEvent(*event, CallerType::System, err);
  if (aDefaultAction) {
    *aDefaultAction = doDefault;
  }
  return err.StealNSResult();
}

// static
nsresult
nsContentUtils::DispatchEvent(nsIDocument* aDoc, nsISupports* aTarget,
                              WidgetEvent& aEvent,
                              EventMessage aEventMessage,
                              bool aCanBubble, bool aCancelable,
                              bool aTrusted, bool *aDefaultAction,
                              bool aOnlyChromeDispatch)
{
  MOZ_ASSERT_IF(aOnlyChromeDispatch, aTrusted);

  nsCOMPtr<EventTarget> target(do_QueryInterface(aTarget));

  aEvent.mTime = PR_Now();

  aEvent.mSpecifiedEventType = GetEventTypeFromMessage(aEventMessage);
  aEvent.SetDefaultComposed();
  aEvent.SetDefaultComposedInNativeAnonymousContent();

  aEvent.mFlags.mBubbles = aCanBubble;
  aEvent.mFlags.mCancelable = aCancelable;
  aEvent.mFlags.mOnlyChromeDispatch = aOnlyChromeDispatch;

  aEvent.mTarget = target;

  nsEventStatus status = nsEventStatus_eIgnore;
  nsresult rv = EventDispatcher::DispatchDOMEvent(target, &aEvent, nullptr,
                                                  nullptr, &status);
  if (aDefaultAction) {
    *aDefaultAction = (status != nsEventStatus_eConsumeNoDefault);
  }
  return rv;
}

nsresult
nsContentUtils::DispatchChromeEvent(nsIDocument *aDoc,
                                    nsISupports *aTarget,
                                    const nsAString& aEventName,
                                    bool aCanBubble, bool aCancelable,
                                    bool* aDefaultAction)
{

  RefPtr<Event> event;
  nsCOMPtr<EventTarget> target;
  nsresult rv = GetEventAndTarget(aDoc, aTarget, aEventName, aCanBubble,
                                  aCancelable, true, getter_AddRefs(event),
                                  getter_AddRefs(target));
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ASSERTION(aDoc, "GetEventAndTarget lied?");
  if (!aDoc->GetWindow())
    return NS_ERROR_INVALID_ARG;

  EventTarget* piTarget = aDoc->GetWindow()->GetParentTarget();
  if (!piTarget)
    return NS_ERROR_INVALID_ARG;

  ErrorResult err;
  bool defaultActionEnabled =
    piTarget->DispatchEvent(*event, CallerType::System, err);
  if (aDefaultAction) {
    *aDefaultAction = defaultActionEnabled;
  }
  return err.StealNSResult();
}

/* static */
nsresult
nsContentUtils::DispatchFocusChromeEvent(nsPIDOMWindowOuter* aWindow)
{
  MOZ_ASSERT(aWindow);

  nsCOMPtr<nsIDocument> doc = aWindow->GetExtantDoc();
  if (!doc) {
    return NS_ERROR_FAILURE;
  }

  return DispatchChromeEvent(doc, aWindow,
                             NS_LITERAL_STRING("DOMWindowFocus"),
                             true, true);
}

nsresult
nsContentUtils::DispatchEventOnlyToChrome(nsIDocument* aDoc,
                                          nsISupports* aTarget,
                                          const nsAString& aEventName,
                                          bool aCanBubble, bool aCancelable,
                                          bool* aDefaultAction)
{
  return DispatchEvent(aDoc, aTarget, aEventName, aCanBubble, aCancelable,
                       true, aDefaultAction, true);
}

/* static */
Element*
nsContentUtils::MatchElementId(nsIContent *aContent, const nsAtom* aId)
{
  for (nsIContent* cur = aContent;
       cur;
       cur = cur->GetNextNode(aContent)) {
    if (aId == cur->GetID()) {
      return cur->AsElement();
    }
  }

  return nullptr;
}

/* static */
Element *
nsContentUtils::MatchElementId(nsIContent *aContent, const nsAString& aId)
{
  NS_PRECONDITION(!aId.IsEmpty(), "Will match random elements");

  // ID attrs are generally stored as atoms, so just atomize this up front
  RefPtr<nsAtom> id(NS_Atomize(aId));
  if (!id) {
    // OOM, so just bail
    return nullptr;
  }

  return MatchElementId(aContent, id);
}

/* static */
nsIDocument*
nsContentUtils::GetSubdocumentWithOuterWindowId(nsIDocument *aDocument,
                                                uint64_t aOuterWindowId)
{
  if (!aDocument || !aOuterWindowId) {
    return nullptr;
  }

  RefPtr<nsGlobalWindowOuter> window =
    nsGlobalWindowOuter::GetOuterWindowWithId(aOuterWindowId);
  if (!window) {
    return nullptr;
  }

  nsCOMPtr<nsPIDOMWindowOuter> outerWindow = window->AsOuter();
  nsCOMPtr<nsIDocument> foundDoc = outerWindow->GetDoc();
  if (nsContentUtils::ContentIsCrossDocDescendantOf(foundDoc, aDocument)) {
    // Note that ContentIsCrossDocDescendantOf will return true if
    // foundDoc == aDocument.
    return foundDoc;
  }

  return nullptr;
}

/* static */
void
nsContentUtils::RegisterShutdownObserver(nsIObserver* aObserver)
{
  nsCOMPtr<nsIObserverService> observerService =
    mozilla::services::GetObserverService();
  if (observerService) {
    observerService->AddObserver(aObserver,
                                 NS_XPCOM_SHUTDOWN_OBSERVER_ID,
                                 false);
  }
}

/* static */
void
nsContentUtils::UnregisterShutdownObserver(nsIObserver* aObserver)
{
  nsCOMPtr<nsIObserverService> observerService =
    mozilla::services::GetObserverService();
  if (observerService) {
    observerService->RemoveObserver(aObserver, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
  }
}

/* static */
bool
nsContentUtils::HasNonEmptyAttr(const nsIContent* aContent,
                                int32_t aNameSpaceID,
                                nsAtom* aName)
{
  static Element::AttrValuesArray strings[] = {&nsGkAtoms::_empty, nullptr};
  return aContent->IsElement() &&
    aContent->AsElement()->FindAttrValueIn(aNameSpaceID, aName, strings, eCaseMatters)
      == Element::ATTR_VALUE_NO_MATCH;
}

/* static */
bool
nsContentUtils::HasMutationListeners(nsINode* aNode,
                                     uint32_t aType,
                                     nsINode* aTargetForSubtreeModified)
{
  nsIDocument* doc = aNode->OwnerDoc();

  // global object will be null for documents that don't have windows.
  nsPIDOMWindowInner* window = doc->GetInnerWindow();
  // This relies on EventListenerManager::AddEventListener, which sets
  // all mutation bits when there is a listener for DOMSubtreeModified event.
  if (window && !window->HasMutationListeners(aType)) {
    return false;
  }

  if (aNode->IsContent() && aNode->AsContent()->ChromeOnlyAccess()) {
    return false;
  }

  doc->MayDispatchMutationEvent(aTargetForSubtreeModified);

  // If we have a window, we can check it for mutation listeners now.
  if (aNode->IsInUncomposedDoc()) {
    nsCOMPtr<EventTarget> piTarget(do_QueryInterface(window));
    if (piTarget) {
      EventListenerManager* manager = piTarget->GetExistingListenerManager();
      if (manager && manager->HasMutationListeners()) {
        return true;
      }
    }
  }

  // If we have a window, we know a mutation listener is registered, but it
  // might not be in our chain.  If we don't have a window, we might have a
  // mutation listener.  Check quickly to see.
  while (aNode) {
    EventListenerManager* manager = aNode->GetExistingListenerManager();
    if (manager && manager->HasMutationListeners()) {
      return true;
    }

    if (aNode->IsContent()) {
      nsIContent* insertionPoint = aNode->AsContent()->GetXBLInsertionPoint();
      if (insertionPoint) {
        aNode = insertionPoint->GetParent();
        MOZ_ASSERT(aNode);
        continue;
      }
    }
    aNode = aNode->GetParentNode();
  }

  return false;
}

/* static */
bool
nsContentUtils::HasMutationListeners(nsIDocument* aDocument,
                                     uint32_t aType)
{
  nsPIDOMWindowInner* window = aDocument ?
    aDocument->GetInnerWindow() : nullptr;

  // This relies on EventListenerManager::AddEventListener, which sets
  // all mutation bits when there is a listener for DOMSubtreeModified event.
  return !window || window->HasMutationListeners(aType);
}

void
nsContentUtils::MaybeFireNodeRemoved(nsINode* aChild, nsINode* aParent,
                                     nsIDocument* aOwnerDoc)
{
  NS_PRECONDITION(aChild, "Missing child");
  NS_PRECONDITION(aChild->GetParentNode() == aParent, "Wrong parent");
  NS_PRECONDITION(aChild->OwnerDoc() == aOwnerDoc, "Wrong owner-doc");

  // Having an explicit check here since it's an easy mistake to fall into,
  // and there might be existing code with problems. We'd rather be safe
  // than fire DOMNodeRemoved in all corner cases. We also rely on it for
  // nsAutoScriptBlockerSuppressNodeRemoved.
  if (!IsSafeToRunScript()) {
    // This checks that IsSafeToRunScript is true since we don't want to fire
    // events when that is false. We can't rely on EventDispatcher to assert
    // this in this situation since most of the time there are no mutation
    // event listeners, in which case we won't even attempt to dispatch events.
    // However this also allows for two exceptions. First off, we don't assert
    // if the mutation happens to native anonymous content since we never fire
    // mutation events on such content anyway.
    // Second, we don't assert if sDOMNodeRemovedSuppressCount is true since
    // that is a know case when we'd normally fire a mutation event, but can't
    // make that safe and so we suppress it at this time. Ideally this should
    // go away eventually.
    if (!(aChild->IsContent() && aChild->AsContent()->IsInNativeAnonymousSubtree()) &&
        !sDOMNodeRemovedSuppressCount) {
      NS_ERROR("Want to fire DOMNodeRemoved event, but it's not safe");
      WarnScriptWasIgnored(aOwnerDoc);
    }
    return;
  }

  if (HasMutationListeners(aChild,
        NS_EVENT_BITS_MUTATION_NODEREMOVED, aParent)) {
    InternalMutationEvent mutation(true, eLegacyNodeRemoved);
    mutation.mRelatedNode = do_QueryInterface(aParent);

    mozAutoSubtreeModified subtree(aOwnerDoc, aParent);
    EventDispatcher::Dispatch(aChild, nullptr, &mutation);
  }
}

void
nsContentUtils::UnmarkGrayJSListenersInCCGenerationDocuments()
{
  if (!sEventListenerManagersHash) {
    return;
  }

  for (auto i = sEventListenerManagersHash->Iter(); !i.Done(); i.Next()) {
    auto entry = static_cast<EventListenerManagerMapEntry*>(i.Get());
    nsINode* n = static_cast<nsINode*>(entry->mListenerManager->GetTarget());
    if (n && n->IsInUncomposedDoc() &&
        nsCCUncollectableMarker::InGeneration(n->OwnerDoc()->GetMarkedCCGeneration())) {
      entry->mListenerManager->MarkForCC();
    }
  }
}

/* static */
void
nsContentUtils::TraverseListenerManager(nsINode *aNode,
                                        nsCycleCollectionTraversalCallback &cb)
{
  if (!sEventListenerManagersHash) {
    // We're already shut down, just return.
    return;
  }

  auto entry = static_cast<EventListenerManagerMapEntry*>
                          (sEventListenerManagersHash->Search(aNode));
  if (entry) {
    CycleCollectionNoteChild(cb, entry->mListenerManager.get(),
                             "[via hash] mListenerManager");
  }
}

EventListenerManager*
nsContentUtils::GetListenerManagerForNode(nsINode *aNode)
{
  if (!sEventListenerManagersHash) {
    // We're already shut down, don't bother creating an event listener
    // manager.

    return nullptr;
  }

  auto entry =
    static_cast<EventListenerManagerMapEntry*>
               (sEventListenerManagersHash->Add(aNode, fallible));

  if (!entry) {
    return nullptr;
  }

  if (!entry->mListenerManager) {
    entry->mListenerManager = new EventListenerManager(aNode);

    aNode->SetFlags(NODE_HAS_LISTENERMANAGER);
  }

  return entry->mListenerManager;
}

EventListenerManager*
nsContentUtils::GetExistingListenerManagerForNode(const nsINode *aNode)
{
  if (!aNode->HasFlag(NODE_HAS_LISTENERMANAGER)) {
    return nullptr;
  }

  if (!sEventListenerManagersHash) {
    // We're already shut down, don't bother creating an event listener
    // manager.

    return nullptr;
  }

  auto entry = static_cast<EventListenerManagerMapEntry*>
                          (sEventListenerManagersHash->Search(aNode));
  if (entry) {
    return entry->mListenerManager;
  }

  return nullptr;
}

/* static */
void
nsContentUtils::RemoveListenerManager(nsINode *aNode)
{
  if (sEventListenerManagersHash) {
    auto entry = static_cast<EventListenerManagerMapEntry*>
                            (sEventListenerManagersHash->Search(aNode));
    if (entry) {
      RefPtr<EventListenerManager> listenerManager;
      listenerManager.swap(entry->mListenerManager);
      // Remove the entry and *then* do operations that could cause further
      // modification of sEventListenerManagersHash.  See bug 334177.
      sEventListenerManagersHash->RawRemove(entry);
      if (listenerManager) {
        listenerManager->Disconnect();
      }
    }
  }
}

/* static */
bool
nsContentUtils::IsValidNodeName(nsAtom *aLocalName, nsAtom *aPrefix,
                                int32_t aNamespaceID)
{
  if (aNamespaceID == kNameSpaceID_Unknown) {
    return false;
  }

  if (!aPrefix) {
    // If the prefix is null, then either the QName must be xmlns or the
    // namespace must not be XMLNS.
    return (aLocalName == nsGkAtoms::xmlns) ==
           (aNamespaceID == kNameSpaceID_XMLNS);
  }

  // If the prefix is non-null then the namespace must not be null.
  if (aNamespaceID == kNameSpaceID_None) {
    return false;
  }

  // If the namespace is the XMLNS namespace then the prefix must be xmlns,
  // but the localname must not be xmlns.
  if (aNamespaceID == kNameSpaceID_XMLNS) {
    return aPrefix == nsGkAtoms::xmlns && aLocalName != nsGkAtoms::xmlns;
  }

  // If the namespace is not the XMLNS namespace then the prefix must not be
  // xmlns.
  // If the namespace is the XML namespace then the prefix can be anything.
  // If the namespace is not the XML namespace then the prefix must not be xml.
  return aPrefix != nsGkAtoms::xmlns &&
         (aNamespaceID == kNameSpaceID_XML || aPrefix != nsGkAtoms::xml);
}

/* static */
nsresult
nsContentUtils::CreateContextualFragment(nsINode* aContextNode,
                                         const nsAString& aFragment,
                                         bool aPreventScriptExecution,
                                         nsIDOMDocumentFragment** aReturn)
{
  ErrorResult rv;
  *aReturn = CreateContextualFragment(aContextNode, aFragment,
                                      aPreventScriptExecution, rv).take();
  return rv.StealNSResult();
}

already_AddRefed<DocumentFragment>
nsContentUtils::CreateContextualFragment(nsINode* aContextNode,
                                         const nsAString& aFragment,
                                         bool aPreventScriptExecution,
                                         SanitizeFragments aSanitize,
                                         ErrorResult& aRv)
{
  if (!aContextNode) {
    aRv.Throw(NS_ERROR_INVALID_ARG);
    return nullptr;
  }

  // If we don't have a document here, we can't get the right security context
  // for compiling event handlers... so just bail out.
  nsCOMPtr<nsIDocument> document = aContextNode->OwnerDoc();
  bool isHTML = document->IsHTMLDocument();
#ifdef DEBUG
  nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(document);
  NS_ASSERTION(!isHTML || htmlDoc, "Should have HTMLDocument here!");
#endif

  if (isHTML) {
    RefPtr<DocumentFragment> frag =
      new DocumentFragment(document->NodeInfoManager());

    nsCOMPtr<nsIContent> contextAsContent = do_QueryInterface(aContextNode);
    if (contextAsContent && !contextAsContent->IsElement()) {
      contextAsContent = contextAsContent->GetParent();
      if (contextAsContent && !contextAsContent->IsElement()) {
        // can this even happen?
        contextAsContent = nullptr;
      }
    }

    if (contextAsContent && !contextAsContent->IsHTMLElement(nsGkAtoms::html)) {
      aRv = ParseFragmentHTML(aFragment, frag,
                              contextAsContent->NodeInfo()->NameAtom(),
                              contextAsContent->GetNameSpaceID(),
                              (document->GetCompatibilityMode() ==
                               eCompatibility_NavQuirks),
                              aPreventScriptExecution,
                              aSanitize);
    } else {
      aRv = ParseFragmentHTML(aFragment, frag,
                              nsGkAtoms::body,
                              kNameSpaceID_XHTML,
                              (document->GetCompatibilityMode() ==
                               eCompatibility_NavQuirks),
                              aPreventScriptExecution,
                              aSanitize);
    }

    return frag.forget();
  }

  AutoTArray<nsString, 32> tagStack;
  nsAutoString uriStr, nameStr;
  nsCOMPtr<nsIContent> content = do_QueryInterface(aContextNode);
  // just in case we have a text node
  if (content && !content->IsElement())
    content = content->GetParent();

  while (content && content->IsElement()) {
    nsString& tagName = *tagStack.AppendElement();
    tagName = content->NodeInfo()->QualifiedName();

    // see if we need to add xmlns declarations
    uint32_t count = content->AsElement()->GetAttrCount();
    bool setDefaultNamespace = false;
    if (count > 0) {
      uint32_t index;

      for (index = 0; index < count; index++) {
        const BorrowedAttrInfo info = content->AsElement()->GetAttrInfoAt(index);
        const nsAttrName* name = info.mName;
        if (name->NamespaceEquals(kNameSpaceID_XMLNS)) {
          info.mValue->ToString(uriStr);

          // really want something like nsXMLContentSerializer::SerializeAttr
          tagName.AppendLiteral(" xmlns"); // space important
          if (name->GetPrefix()) {
            tagName.Append(char16_t(':'));
            name->LocalName()->ToString(nameStr);
            tagName.Append(nameStr);
          } else {
            setDefaultNamespace = true;
          }
          tagName.AppendLiteral(R"(=")");
          tagName.Append(uriStr);
          tagName.Append('"');
        }
      }
    }

    if (!setDefaultNamespace) {
      mozilla::dom::NodeInfo* info = content->NodeInfo();
      if (!info->GetPrefixAtom() &&
          info->NamespaceID() != kNameSpaceID_None) {
        // We have no namespace prefix, but have a namespace ID.  Push
        // default namespace attr in, so that our kids will be in our
        // namespace.
        info->GetNamespaceURI(uriStr);
        tagName.AppendLiteral(R"( xmlns=")");
        tagName.Append(uriStr);
        tagName.Append('"');
      }
    }

    content = content->GetParent();
  }

  nsCOMPtr<nsIDOMDocumentFragment> frag;
  aRv = ParseFragmentXML(aFragment, document, tagStack,
                         aPreventScriptExecution, getter_AddRefs(frag),
                         aSanitize);
  return frag.forget().downcast<DocumentFragment>();
}

/* static */
void
nsContentUtils::DropFragmentParsers()
{
  NS_IF_RELEASE(sHTMLFragmentParser);
  NS_IF_RELEASE(sXMLFragmentParser);
  NS_IF_RELEASE(sXMLFragmentSink);
}

/* static */
void
nsContentUtils::XPCOMShutdown()
{
  nsContentUtils::DropFragmentParsers();
}

/* static */
nsresult
nsContentUtils::ParseFragmentHTML(const nsAString& aSourceBuffer,
                                  nsIContent* aTargetNode,
                                  nsAtom* aContextLocalName,
                                  int32_t aContextNamespace,
                                  bool aQuirks,
                                  bool aPreventScriptExecution,
                                  SanitizeFragments aSanitize)
{
  AutoTimelineMarker m(aTargetNode->OwnerDoc()->GetDocShell(), "Parse HTML");

  if (nsContentUtils::sFragmentParsingActive) {
    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
    return NS_ERROR_DOM_INVALID_STATE_ERR;
  }
  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
  nsContentUtils::sFragmentParsingActive = true;
  if (!sHTMLFragmentParser) {
    NS_ADDREF(sHTMLFragmentParser = new nsHtml5StringParser());
    // Now sHTMLFragmentParser owns the object
  }

  nsIContent* target = aTargetNode;

  // If this is a chrome-privileged document, create a fragment first, and
  // sanitize it before insertion.
  RefPtr<DocumentFragment> fragment;
  if (aSanitize != NeverSanitize &&
      IsSystemPrincipal(aTargetNode->NodePrincipal())) {
    fragment = new DocumentFragment(aTargetNode->OwnerDoc()->NodeInfoManager());
    target = fragment;
  }

  nsresult rv =
    sHTMLFragmentParser->ParseFragment(aSourceBuffer,
                                       target,
                                       aContextLocalName,
                                       aContextNamespace,
                                       aQuirks,
                                       aPreventScriptExecution);
  NS_ENSURE_SUCCESS(rv, rv);

  if (fragment) {
    // Don't fire mutation events for nodes removed by the sanitizer.
    nsAutoScriptBlockerSuppressNodeRemoved scriptBlocker;

    nsTreeSanitizer sanitizer(nsIParserUtils::SanitizerAllowStyle |
                              nsIParserUtils::SanitizerAllowComments |
                              nsIParserUtils::SanitizerDropForms |
                              nsIParserUtils::SanitizerLogRemovals);
    sanitizer.Sanitize(fragment);

    ErrorResult error;
    aTargetNode->AppendChild(*fragment, error);
    rv = error.StealNSResult();
  }

  return rv;
}

/* static */
nsresult
nsContentUtils::ParseDocumentHTML(const nsAString& aSourceBuffer,
                                  nsIDocument* aTargetDocument,
                                  bool aScriptingEnabledForNoscriptParsing)
{
  AutoTimelineMarker m(aTargetDocument->GetDocShell(), "Parse HTML");

  if (nsContentUtils::sFragmentParsingActive) {
    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
    return NS_ERROR_DOM_INVALID_STATE_ERR;
  }
  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
  nsContentUtils::sFragmentParsingActive = true;
  if (!sHTMLFragmentParser) {
    NS_ADDREF(sHTMLFragmentParser = new nsHtml5StringParser());
    // Now sHTMLFragmentParser owns the object
  }
  nsresult rv =
    sHTMLFragmentParser->ParseDocument(aSourceBuffer,
                                       aTargetDocument,
                                       aScriptingEnabledForNoscriptParsing);
  return rv;
}

/* static */
nsresult
nsContentUtils::ParseFragmentXML(const nsAString& aSourceBuffer,
                                 nsIDocument* aDocument,
                                 nsTArray<nsString>& aTagStack,
                                 bool aPreventScriptExecution,
                                 nsIDOMDocumentFragment** aReturn,
                                 SanitizeFragments aSanitize)
{
  AutoTimelineMarker m(aDocument->GetDocShell(), "Parse XML");

  if (nsContentUtils::sFragmentParsingActive) {
    NS_NOTREACHED("Re-entrant fragment parsing attempted.");
    return NS_ERROR_DOM_INVALID_STATE_ERR;
  }
  mozilla::AutoRestore<bool> guard(nsContentUtils::sFragmentParsingActive);
  nsContentUtils::sFragmentParsingActive = true;
  if (!sXMLFragmentParser) {
    nsCOMPtr<nsIParser> parser = do_CreateInstance(kCParserCID);
    parser.forget(&sXMLFragmentParser);
    // sXMLFragmentParser now owns the parser
  }
  if (!sXMLFragmentSink) {
    NS_NewXMLFragmentContentSink(&sXMLFragmentSink);
    // sXMLFragmentSink now owns the sink
  }
  nsCOMPtr<nsIContentSink> contentsink = do_QueryInterface(sXMLFragmentSink);
  MOZ_ASSERT(contentsink, "Sink doesn't QI to nsIContentSink!");
  sXMLFragmentParser->SetContentSink(contentsink);

  sXMLFragmentSink->SetTargetDocument(aDocument);
  sXMLFragmentSink->SetPreventScriptExecution(aPreventScriptExecution);

  nsresult rv =
    sXMLFragmentParser->ParseFragment(aSourceBuffer,
                                      aTagStack);
  if (NS_FAILED(rv)) {
    // Drop the fragment parser and sink that might be in an inconsistent state
    NS_IF_RELEASE(sXMLFragmentParser);
    NS_IF_RELEASE(sXMLFragmentSink);
    return rv;
  }

  rv = sXMLFragmentSink->FinishFragmentParsing(aReturn);

  sXMLFragmentParser->Reset();
  NS_ENSURE_SUCCESS(rv, rv);

  // If this is a chrome-privileged document, sanitize the fragment before
  // returning.
  if (aSanitize != NeverSanitize &&
      IsSystemPrincipal(aDocument->NodePrincipal())) {
    // Don't fire mutation events for nodes removed by the sanitizer.
    nsAutoScriptBlockerSuppressNodeRemoved scriptBlocker;

    RefPtr<DocumentFragment> fragment = static_cast<DocumentFragment*>(*aReturn);

    nsTreeSanitizer sanitizer(nsIParserUtils::SanitizerAllowStyle |
                              nsIParserUtils::SanitizerAllowComments |
                              nsIParserUtils::SanitizerDropForms |
                              nsIParserUtils::SanitizerLogRemovals);
    sanitizer.Sanitize(fragment);
  }

  return rv;
}

/* static */
nsresult
nsContentUtils::ConvertToPlainText(const nsAString& aSourceBuffer,
                                   nsAString& aResultBuffer,
                                   uint32_t aFlags,
                                   uint32_t aWrapCol)
{
  nsCOMPtr<nsIURI> uri;
  NS_NewURI(getter_AddRefs(uri), "about:blank");
  nsCOMPtr<nsIPrincipal> principal = NullPrincipal::CreateWithoutOriginAttributes();
  nsCOMPtr<nsIDOMDocument> domDocument;
  nsresult rv = NS_NewDOMDocument(getter_AddRefs(domDocument),
                                  EmptyString(),
                                  EmptyString(),
                                  nullptr,
                                  uri,
                                  uri,
                                  principal,
                                  true,
                                  nullptr,
                                  DocumentFlavorHTML);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIDocument> document = do_QueryInterface(domDocument);
  rv = nsContentUtils::ParseDocumentHTML(aSourceBuffer, document,
    !(aFlags & nsIDocumentEncoder::OutputNoScriptContent));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIDocumentEncoder> encoder = do_CreateInstance(
    "@mozilla.org/layout/documentEncoder;1?type=text/plain");

  rv = encoder->Init(domDocument, NS_LITERAL_STRING("text/plain"), aFlags);
  NS_ENSURE_SUCCESS(rv, rv);

  encoder->SetWrapColumn(aWrapCol);

  return encoder->EncodeToString(aResultBuffer);
}

/* static */
nsresult
nsContentUtils::SetNodeTextContent(nsIContent* aContent,
                                   const nsAString& aValue,
                                   bool aTryReuse)
{
  // Fire DOMNodeRemoved mutation events before we do anything else.
  nsCOMPtr<nsIContent> owningContent;

  // Batch possible DOMSubtreeModified events.
  mozAutoSubtreeModified subtree(nullptr, nullptr);

  // Scope firing mutation events so that we don't carry any state that
  // might be stale
  {
    // We're relying on mozAutoSubtreeModified to keep a strong reference if
    // needed.
    nsIDocument* doc = aContent->OwnerDoc();

    // Optimize the common case of there being no observers
    if (HasMutationListeners(doc, NS_EVENT_BITS_MUTATION_NODEREMOVED)) {
      subtree.UpdateTarget(doc, nullptr);
      owningContent = aContent;
      nsCOMPtr<nsINode> child;
      bool skipFirst = aTryReuse;
      for (child = aContent->GetFirstChild();
           child && child->GetParentNode() == aContent;
           child = child->GetNextSibling()) {
        if (skipFirst && child->IsText()) {
          skipFirst = false;
          continue;
        }
        nsContentUtils::MaybeFireNodeRemoved(child, aContent, doc);
      }
    }
  }

  // Might as well stick a batch around this since we're performing several
  // mutations.
  mozAutoDocUpdate updateBatch(aContent->GetComposedDoc(),
    UPDATE_CONTENT_MODEL, true);
  nsAutoMutationBatch mb;

  if (aTryReuse && !aValue.IsEmpty()) {
    // Let's remove nodes until we find a eTEXT.
    while (aContent->HasChildren()) {
      nsIContent* child = aContent->GetFirstChild();
      if (child->IsText()) {
        break;
      }
      aContent->RemoveChildNode(child, true);
    }

    // If we have a node, it must be a eTEXT and we reuse it.
    if (aContent->HasChildren()) {
      nsIContent* child = aContent->GetFirstChild();
      nsresult rv = child->AsText()->SetText(aValue, true);
      NS_ENSURE_SUCCESS(rv, rv);

      // All the following nodes, if they exist, must be deleted.
      while (nsIContent* nextChild = child->GetNextSibling()) {
        aContent->RemoveChildNode(nextChild, true);
      }
    }

    if (aContent->HasChildren()) {
      return NS_OK;
    }
  }
  else {
    mb.Init(aContent, true, false);
    while (aContent->HasChildren()) {
      aContent->RemoveChildNode(aContent->GetFirstChild(), true);
    }
  }
  mb.RemovalDone();

  if (aValue.IsEmpty()) {
    return NS_OK;
  }

  RefPtr<nsTextNode> textContent =
    new nsTextNode(aContent->NodeInfo()->NodeInfoManager());

  textContent->SetText(aValue, true);

  nsresult rv = aContent->AppendChildTo(textContent, true);
  mb.NodesAdded();
  return rv;
}

static bool
AppendNodeTextContentsRecurse(nsINode* aNode, nsAString& aResult,
                              const fallible_t& aFallible)
{
  for (nsIContent* child = aNode->GetFirstChild();
       child;
       child = child->GetNextSibling()) {
    if (child->IsElement()) {
      bool ok = AppendNodeTextContentsRecurse(child, aResult,
                                              aFallible);
      if (!ok) {
        return false;
      }
    }
    else if (Text* text = child->GetAsText()) {
      bool ok = text->AppendTextTo(aResult, aFallible);
      if (!ok) {
        return false;
      }
    }
  }

  return true;
}

/* static */
bool
nsContentUtils::AppendNodeTextContent(nsINode* aNode, bool aDeep,
                                      nsAString& aResult,
                                      const fallible_t& aFallible)
{
  if (Text* text = aNode->GetAsText()) {
    return text->AppendTextTo(aResult, aFallible);
  }
  if (aDeep) {
    return AppendNodeTextContentsRecurse(aNode, aResult, aFallible);
  }

  for (nsIContent* child = aNode->GetFirstChild();
       child;
       child = child->GetNextSibling()) {
    if (Text* text = child->GetAsText()) {
      bool ok = text->AppendTextTo(aResult, fallible);
      if (!ok) {
        return false;
      }
    }
  }
  return true;
}

bool
nsContentUtils::HasNonEmptyTextContent(nsINode* aNode,
                                       TextContentDiscoverMode aDiscoverMode)
{
  for (nsIContent* child = aNode->GetFirstChild();
       child;
       child = child->GetNextSibling()) {
    if (child->IsText() &&
        child->TextLength() > 0) {
        return true;
    }

    if (aDiscoverMode == eRecurseIntoChildren &&
        HasNonEmptyTextContent(child, aDiscoverMode)) {
      return true;
    }
  }

  return false;
}

/* static */
bool
nsContentUtils::IsInSameAnonymousTree(const nsINode* aNode,
                                      const nsIContent* aContent)
{
  NS_PRECONDITION(aNode,
                  "Must have a node to work with");
  NS_PRECONDITION(aContent,
                  "Must have a content to work with");

  if (!aNode->IsContent()) {
    /**
     * The root isn't an nsIContent, so it's a document or attribute.  The only
     * nodes in the same anonymous subtree as it will have a null
     * bindingParent.
     *
     * XXXbz strictly speaking, that's not true for attribute nodes.
     */
    return aContent->GetBindingParent() == nullptr;
  }

  return aNode->AsContent()->GetBindingParent() == aContent->GetBindingParent();
}

/* static */
void
nsContentUtils::NotifyInstalledMenuKeyboardListener(bool aInstalling)
{
  IMEStateManager::OnInstalledMenuKeyboardListener(aInstalling);
}

/* static */ bool
nsContentUtils::SchemeIs(nsIURI* aURI, const char* aScheme)
{
  nsCOMPtr<nsIURI> baseURI = NS_GetInnermostURI(aURI);
  NS_ENSURE_TRUE(baseURI, false);

  bool isScheme = false;
  return NS_SUCCEEDED(baseURI->SchemeIs(aScheme, &isScheme)) && isScheme;
}

bool
nsContentUtils::IsSystemPrincipal(nsIPrincipal* aPrincipal)
{
  MOZ_ASSERT(IsInitialized());
  return aPrincipal == sSystemPrincipal;
}

bool
nsContentUtils::IsExpandedPrincipal(nsIPrincipal* aPrincipal)
{
  nsCOMPtr<nsIExpandedPrincipal> ep = do_QueryInterface(aPrincipal);
  return !!ep;
}

nsIPrincipal*
nsContentUtils::GetSystemPrincipal()
{
  MOZ_ASSERT(IsInitialized());
  return sSystemPrincipal;
}

bool
nsContentUtils::CombineResourcePrincipals(nsCOMPtr<nsIPrincipal>* aResourcePrincipal,
                                          nsIPrincipal* aExtraPrincipal)
{
  if (!aExtraPrincipal) {
    return false;
  }
  if (!*aResourcePrincipal) {
    *aResourcePrincipal = aExtraPrincipal;
    return true;
  }
  if (*aResourcePrincipal == aExtraPrincipal) {
    return false;
  }
  bool subsumes;
  if (NS_SUCCEEDED((*aResourcePrincipal)->Subsumes(aExtraPrincipal, &subsumes)) &&
      subsumes) {
    return false;
  }
  *aResourcePrincipal = sSystemPrincipal;
  return true;
}

/* static */
void
nsContentUtils::TriggerLink(nsIContent *aContent, nsPresContext *aPresContext,
                            nsIURI *aLinkURI, const nsString &aTargetSpec,
                            bool aClick, bool aIsUserTriggered,
                            bool aIsTrusted)
{
  NS_ASSERTION(aPresContext, "Need a nsPresContext");
  NS_PRECONDITION(aLinkURI, "No link URI");

  if (aContent->IsEditable()) {
    return;
  }

  nsILinkHandler *handler = aPresContext->GetLinkHandler();
  if (!handler) {
    return;
  }

  if (!aClick) {
    handler->OnOverLink(aContent, aLinkURI, aTargetSpec.get());
    return;
  }

  // Check that this page is allowed to load this URI.
  nsresult proceed = NS_OK;

  if (sSecurityManager) {
    uint32_t flag =
      aIsUserTriggered ?
      (uint32_t)nsIScriptSecurityManager::STANDARD :
      (uint32_t)nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT;
    proceed =
      sSecurityManager->CheckLoadURIWithPrincipal(aContent->NodePrincipal(),
                                                  aLinkURI, flag);
  }

  // Only pass off the click event if the script security manager says it's ok.
  // We need to rest aTargetSpec for forced downloads.
  if (NS_SUCCEEDED(proceed)) {

    // A link/area element with a download attribute is allowed to set
    // a pseudo Content-Disposition header.
    // For security reasons we only allow websites to declare same-origin resources
    // as downloadable. If this check fails we will just do the normal thing
    // (i.e. navigate to the resource).
    nsAutoString fileName;
    if ((!aContent->IsHTMLElement(nsGkAtoms::a) &&
         !aContent->IsHTMLElement(nsGkAtoms::area) &&
         !aContent->IsSVGElement(nsGkAtoms::a)) ||
        !aContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::download, fileName) ||
        NS_FAILED(aContent->NodePrincipal()->CheckMayLoad(aLinkURI, false, true))) {
      fileName.SetIsVoid(true); // No actionable download attribute was found.
    }

    handler->OnLinkClick(aContent, aLinkURI,
                         fileName.IsVoid() ? aTargetSpec.get() : EmptyString().get(),
                         fileName, nullptr, -1, nullptr, aIsTrusted,
                         aContent->NodePrincipal());
  }
}

/* static */
void
nsContentUtils::GetLinkLocation(Element* aElement, nsString& aLocationString)
{
  nsCOMPtr<nsIURI> hrefURI = aElement->GetHrefURI();
  if (hrefURI) {
    nsAutoCString specUTF8;
    nsresult rv = hrefURI->GetSpec(specUTF8);
    if (NS_SUCCEEDED(rv))
      CopyUTF8toUTF16(specUTF8, aLocationString);
  }
}

/* static */
nsIWidget*
nsContentUtils::GetTopLevelWidget(nsIWidget* aWidget)
{
  if (!aWidget)
    return nullptr;

  return aWidget->GetTopLevelWidget();
}

/* static */
const nsDependentString
nsContentUtils::GetLocalizedEllipsis()
{
  static char16_t sBuf[4] = { 0, 0, 0, 0 };
  if (!sBuf[0]) {
    nsAutoString tmp;
    Preferences::GetLocalizedString("intl.ellipsis", tmp);
    uint32_t len = std::min(uint32_t(tmp.Length()),
                          uint32_t(ArrayLength(sBuf) - 1));
    CopyUnicodeTo(tmp, 0, sBuf, len);
    if (!sBuf[0])
      sBuf[0] = char16_t(0x2026);
  }
  return nsDependentString(sBuf);
}

/* static */
void
nsContentUtils::AddScriptBlocker()
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!sScriptBlockerCount) {
    MOZ_ASSERT(sRunnersCountAtFirstBlocker == 0,
               "Should not already have a count");
    sRunnersCountAtFirstBlocker = sBlockedScriptRunners ? sBlockedScriptRunners->Length() : 0;
  }
  ++sScriptBlockerCount;
}

#ifdef DEBUG
static bool sRemovingScriptBlockers = false;
#endif

/* static */
void
nsContentUtils::RemoveScriptBlocker()
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(!sRemovingScriptBlockers);
  NS_ASSERTION(sScriptBlockerCount != 0, "Negative script blockers");
  --sScriptBlockerCount;
  if (sScriptBlockerCount) {
    return;
  }

  if (!sBlockedScriptRunners) {
    return;
  }

  uint32_t firstBlocker = sRunnersCountAtFirstBlocker;
  uint32_t lastBlocker = sBlockedScriptRunners->Length();
  uint32_t originalFirstBlocker = firstBlocker;
  uint32_t blockersCount = lastBlocker - firstBlocker;
  sRunnersCountAtFirstBlocker = 0;
  NS_ASSERTION(firstBlocker <= lastBlocker,
               "bad sRunnersCountAtFirstBlocker");

  while (firstBlocker < lastBlocker) {
    nsCOMPtr<nsIRunnable> runnable;
    runnable.swap((*sBlockedScriptRunners)[firstBlocker]);
    ++firstBlocker;

    // Calling the runnable can reenter us
    runnable->Run();
    // So can dropping the reference to the runnable
    runnable = nullptr;

    NS_ASSERTION(sRunnersCountAtFirstBlocker == 0,
                 "Bad count");
    NS_ASSERTION(!sScriptBlockerCount, "This is really bad");
  }
#ifdef DEBUG
  AutoRestore<bool> removingScriptBlockers(sRemovingScriptBlockers);
  sRemovingScriptBlockers = true;
#endif
  sBlockedScriptRunners->RemoveElementsAt(originalFirstBlocker, blockersCount);
}

/* static */
nsIWindowProvider*
nsContentUtils::GetWindowProviderForContentProcess()
{
  MOZ_ASSERT(XRE_IsContentProcess());
  return ContentChild::GetSingleton();
}

/* static */
already_AddRefed<nsPIDOMWindowOuter>
nsContentUtils::GetMostRecentNonPBWindow()
{
  nsCOMPtr<nsIWindowMediator> wm = do_GetService(NS_WINDOWMEDIATOR_CONTRACTID);

  nsCOMPtr<mozIDOMWindowProxy> window;
  wm->GetMostRecentNonPBWindow(u"navigator:browser",
                               getter_AddRefs(window));
  nsCOMPtr<nsPIDOMWindowOuter> pwindow;
  pwindow = do_QueryInterface(window);

  return pwindow.forget();
}

/* static */
void
nsContentUtils::WarnScriptWasIgnored(nsIDocument* aDocument)
{
  nsAutoString msg;
  bool privateBrowsing = false;

  if (aDocument) {
    nsCOMPtr<nsIURI> uri = aDocument->GetDocumentURI();
    if (uri) {
      msg.Append(NS_ConvertUTF8toUTF16(uri->GetSpecOrDefault()));
      msg.AppendLiteral(" : ");
    }
    privateBrowsing =
      !!aDocument->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId;
  }

  msg.AppendLiteral("Unable to run script because scripts are blocked internally.");
  LogSimpleConsoleError(msg, "DOM", privateBrowsing);
}

/* static */
void
nsContentUtils::AddScriptRunner(already_AddRefed<nsIRunnable> aRunnable)
{
  nsCOMPtr<nsIRunnable> runnable = aRunnable;
  if (!runnable) {
    return;
  }

  if (sScriptBlockerCount) {
    sBlockedScriptRunners->AppendElement(runnable.forget());
    return;
  }

  runnable->Run();
}

/* static */
void
nsContentUtils::AddScriptRunner(nsIRunnable* aRunnable) {
  nsCOMPtr<nsIRunnable> runnable = aRunnable;
  AddScriptRunner(runnable.forget());
}

/* static */
void
nsContentUtils::RunInStableState(already_AddRefed<nsIRunnable> aRunnable)
{
  MOZ_ASSERT(CycleCollectedJSContext::Get(), "Must be on a script thread!");
  CycleCollectedJSContext::Get()->RunInStableState(Move(aRunnable));
}

/* static */
void
nsContentUtils::AddPendingIDBTransaction(already_AddRefed<nsIRunnable> aTransaction)
{
  MOZ_ASSERT(CycleCollectedJSContext::Get(), "Must be on a script thread!");
  CycleCollectedJSContext::Get()->AddPendingIDBTransaction(Move(aTransaction));
}

/* static */
bool
nsContentUtils::IsInStableOrMetaStableState()
{
  MOZ_ASSERT(CycleCollectedJSContext::Get(), "Must be on a script thread!");
  return CycleCollectedJSContext::Get()->IsInStableOrMetaStableState();
}

/*
 * Helper function for nsContentUtils::ProcessViewportInfo.
 *
 * Handles a single key=value pair. If it corresponds to a valid viewport
 * attribute, add it to the document header data. No validation is done on the
 * value itself (this is done at display time).
 */
static void ProcessViewportToken(nsIDocument *aDocument,
                                 const nsAString &token) {

  /* Iterators. */
  nsAString::const_iterator tip, tail, end;
  token.BeginReading(tip);
  tail = tip;
  token.EndReading(end);

  /* Move tip to the '='. */
  while ((tip != end) && (*tip != '='))
    ++tip;

  /* If we didn't find an '=', punt. */
  if (tip == end)
    return;

  /* Extract the key and value. */
  const nsAString &key =
    nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(Substring(tail, tip),
                                                        true);
  const nsAString &value =
    nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(Substring(++tip, end),
                                                        true);

  /* Check for known keys. If we find a match, insert the appropriate
   * information into the document header. */
  RefPtr<nsAtom> key_atom = NS_Atomize(key);
  if (key_atom == nsGkAtoms::height)
    aDocument->SetHeaderData(nsGkAtoms::viewport_height, value);
  else if (key_atom == nsGkAtoms::width)
    aDocument->SetHeaderData(nsGkAtoms::viewport_width, value);
  else if (key_atom == nsGkAtoms::initial_scale)
    aDocument->SetHeaderData(nsGkAtoms::viewport_initial_scale, value);
  else if (key_atom == nsGkAtoms::minimum_scale)
    aDocument->SetHeaderData(nsGkAtoms::viewport_minimum_scale, value);
  else if (key_atom == nsGkAtoms::maximum_scale)
    aDocument->SetHeaderData(nsGkAtoms::viewport_maximum_scale, value);
  else if (key_atom == nsGkAtoms::user_scalable)
    aDocument->SetHeaderData(nsGkAtoms::viewport_user_scalable, value);
}

#define IS_SEPARATOR(c) ((c == '=') || (c == ',') || (c == ';') || \
                         (c == '\t') || (c == '\n') || (c == '\r'))

/* static */
nsresult
nsContentUtils::ProcessViewportInfo(nsIDocument *aDocument,
                                    const nsAString &viewportInfo) {

  /* We never fail. */
  nsresult rv = NS_OK;

  aDocument->SetHeaderData(nsGkAtoms::viewport, viewportInfo);

  /* Iterators. */
  nsAString::const_iterator tip, tail, end;
  viewportInfo.BeginReading(tip);
  tail = tip;
  viewportInfo.EndReading(end);

  /* Read the tip to the first non-separator character. */
  while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
    ++tip;

  /* Read through and find tokens separated by separators. */
  while (tip != end) {

    /* Synchronize tip and tail. */
    tail = tip;

    /* Advance tip past non-separator characters. */
    while ((tip != end) && !IS_SEPARATOR(*tip))
      ++tip;

    /* Allow white spaces that surround the '=' character */
    if ((tip != end) && (*tip == '=')) {
      ++tip;

      while ((tip != end) && nsCRT::IsAsciiSpace(*tip))
        ++tip;

      while ((tip != end) && !(IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
        ++tip;
    }

    /* Our token consists of the characters between tail and tip. */
    ProcessViewportToken(aDocument, Substring(tail, tip));

    /* Skip separators. */
    while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip)))
      ++tip;
  }

  return rv;

}

#undef IS_SEPARATOR

/* static */
void
nsContentUtils::HidePopupsInDocument(nsIDocument* aDocument)
{
#ifdef MOZ_XUL
  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
  if (pm && aDocument) {
    nsCOMPtr<nsIDocShellTreeItem> docShellToHide = aDocument->GetDocShell();
    if (docShellToHide)
      pm->HidePopupsInDocShell(docShellToHide);
  }
#endif
}

/* static */
already_AddRefed<nsIDragSession>
nsContentUtils::GetDragSession()
{
  nsCOMPtr<nsIDragSession> dragSession;
  nsCOMPtr<nsIDragService> dragService =
    do_GetService("@mozilla.org/widget/dragservice;1");
  if (dragService)
    dragService->GetCurrentSession(getter_AddRefs(dragSession));
  return dragSession.forget();
}

/* static */
nsresult
nsContentUtils::SetDataTransferInEvent(WidgetDragEvent* aDragEvent)
{
  if (aDragEvent->mDataTransfer || !aDragEvent->IsTrusted()) {
    return NS_OK;
  }

  // For dragstart events, the data transfer object is
  // created before the event fires, so it should already be set. For other
  // drag events, get the object from the drag session.
  NS_ASSERTION(aDragEvent->mMessage != eDragStart,
               "draggesture event created without a dataTransfer");

  nsCOMPtr<nsIDragSession> dragSession = GetDragSession();
  NS_ENSURE_TRUE(dragSession, NS_OK); // no drag in progress

  RefPtr<DataTransfer> initialDataTransfer =
    dragSession->GetDataTransfer();
  if (!initialDataTransfer) {
    // A dataTransfer won't exist when a drag was started by some other
    // means, for instance calling the drag service directly, or a drag
    // from another application. In either case, a new dataTransfer should
    // be created that reflects the data.
    initialDataTransfer =
      new DataTransfer(aDragEvent->mTarget, aDragEvent->mMessage, true, -1);

    // now set it in the drag session so we don't need to create it again
    dragSession->SetDataTransfer(initialDataTransfer);
  }

  bool isCrossDomainSubFrameDrop = false;
  if (aDragEvent->mMessage == eDrop) {
    isCrossDomainSubFrameDrop = CheckForSubFrameDrop(dragSession, aDragEvent);
  }

  // each event should use a clone of the original dataTransfer.
  initialDataTransfer->Clone(aDragEvent->mTarget, aDragEvent->mMessage,
                             aDragEvent->mUserCancelled,
                             isCrossDomainSubFrameDrop,
                             getter_AddRefs(aDragEvent->mDataTransfer));
  if (NS_WARN_IF(!aDragEvent->mDataTransfer)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  // for the dragenter and dragover events, initialize the drop effect
  // from the drop action, which platform specific widget code sets before
  // the event is fired based on the keyboard state.
  if (aDragEvent->mMessage == eDragEnter || aDragEvent->mMessage == eDragOver) {
    uint32_t action;
    dragSession->GetDragAction(&action);
    uint32_t effectAllowed = aDragEvent->mDataTransfer->EffectAllowedInt();
    aDragEvent->mDataTransfer->SetDropEffectInt(
                                 FilterDropEffect(action, effectAllowed));
  }
  else if (aDragEvent->mMessage == eDrop ||
           aDragEvent->mMessage == eDragEnd) {
    // For the drop and dragend events, set the drop effect based on the
    // last value that the dropEffect had. This will have been set in
    // EventStateManager::PostHandleEvent for the last dragenter or
    // dragover event.
    aDragEvent->mDataTransfer->SetDropEffectInt(
      initialDataTransfer->DropEffectInt());
  }

  return NS_OK;
}

/* static */
uint32_t
nsContentUtils::FilterDropEffect(uint32_t aAction, uint32_t aEffectAllowed)
{
  // It is possible for the drag action to include more than one action, but
  // the widget code which sets the action from the keyboard state should only
  // be including one. If multiple actions were set, we just consider them in
  //  the following order:
  //   copy, link, move
  if (aAction & nsIDragService::DRAGDROP_ACTION_COPY)
    aAction = nsIDragService::DRAGDROP_ACTION_COPY;
  else if (aAction & nsIDragService::DRAGDROP_ACTION_LINK)
    aAction = nsIDragService::DRAGDROP_ACTION_LINK;
  else if (aAction & nsIDragService::DRAGDROP_ACTION_MOVE)
    aAction = nsIDragService::DRAGDROP_ACTION_MOVE;

  // Filter the action based on the effectAllowed. If the effectAllowed
  // doesn't include the action, then that action cannot be done, so adjust
  // the action to something that is allowed. For a copy, adjust to move or
  // link. For a move, adjust to copy or link. For a link, adjust to move or
  // link. Otherwise, use none.
  if (aAction & aEffectAllowed ||
      aEffectAllowed == nsIDragService::DRAGDROP_ACTION_UNINITIALIZED)
    return aAction;
  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_MOVE)
    return nsIDragService::DRAGDROP_ACTION_MOVE;
  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_COPY)
    return nsIDragService::DRAGDROP_ACTION_COPY;
  if (aEffectAllowed & nsIDragService::DRAGDROP_ACTION_LINK)
    return nsIDragService::DRAGDROP_ACTION_LINK;
  return nsIDragService::DRAGDROP_ACTION_NONE;
}

/* static */
bool
nsContentUtils::CheckForSubFrameDrop(nsIDragSession* aDragSession,
                                     WidgetDragEvent* aDropEvent)
{
  nsCOMPtr<nsIContent> target = do_QueryInterface(aDropEvent->mOriginalTarget);
  if (!target) {
    return true;
  }

  nsIDocument* targetDoc = target->OwnerDoc();
  nsPIDOMWindowOuter* targetWin = targetDoc->GetWindow();
  if (!targetWin) {
    return true;
  }

  nsCOMPtr<nsIDocShellTreeItem> tdsti = targetWin->GetDocShell();
  if (!tdsti) {
    return true;
  }

  // Always allow dropping onto chrome shells.
  if (tdsti->ItemType() == nsIDocShellTreeItem::typeChrome) {
    return false;
  }

  // If there is no source node, then this is a drag from another
  // application, which should be allowed.
  nsCOMPtr<nsIDOMDocument> sourceDocument;
  aDragSession->GetSourceDocument(getter_AddRefs(sourceDocument));
  nsCOMPtr<nsIDocument> doc = do_QueryInterface(sourceDocument);
  if (doc) {
    // Get each successive parent of the source document and compare it to
    // the drop document. If they match, then this is a drag from a child frame.
    do {
      doc = doc->GetParentDocument();
      if (doc == targetDoc) {
        // The drag is from a child frame.
        return true;
      }
    } while (doc);
  }

  return false;
}

/* static */
bool
nsContentUtils::URIIsLocalFile(nsIURI *aURI)
{
  bool isFile;
  nsCOMPtr<nsINetUtil> util = do_QueryInterface(sIOService);

  // Important: we do NOT test the entire URI chain here!
  return util && NS_SUCCEEDED(util->ProtocolHasFlags(aURI,
                                nsIProtocolHandler::URI_IS_LOCAL_FILE,
                                &isFile)) &&
         isFile;
}

/* static */
JSContext *
nsContentUtils::GetCurrentJSContext()
{
  MOZ_ASSERT(IsInitialized());
  if (!IsJSAPIActive()) {
    return nullptr;
  }
  return danger::GetJSContext();
}

template<typename StringType, typename CharType>
void
_ASCIIToLowerInSitu(StringType& aStr)
{
  CharType* iter = aStr.BeginWriting();
  CharType* end = aStr.EndWriting();
  MOZ_ASSERT(iter && end);

  while (iter != end) {
    CharType c = *iter;
    if (c >= 'A' && c <= 'Z') {
      *iter = c + ('a' - 'A');
    }
    ++iter;
  }
}

/* static */
void
nsContentUtils::ASCIIToLower(nsAString& aStr)
{
  return _ASCIIToLowerInSitu<nsAString, char16_t>(aStr);
}

/* static */
void
nsContentUtils::ASCIIToLower(nsACString& aStr)
{
  return _ASCIIToLowerInSitu<nsACString, char>(aStr);
}

template<typename StringType, typename CharType>
void
_ASCIIToLowerCopy(const StringType& aSource, StringType& aDest)
{
  uint32_t len = aSource.Length();
  aDest.SetLength(len);
  MOZ_ASSERT(aDest.Length() == len);

  CharType* dest = aDest.BeginWriting();
  MOZ_ASSERT(dest);

  const CharType* iter = aSource.BeginReading();
  const CharType* end = aSource.EndReading();
  while (iter != end) {
    CharType c = *iter;
    *dest = (c >= 'A' && c <= 'Z') ?
       c + ('a' - 'A') : c;
    ++iter;
    ++dest;
  }
}

/* static */
void
nsContentUtils::ASCIIToLower(const nsAString& aSource, nsAString& aDest) {
  return _ASCIIToLowerCopy<nsAString, char16_t>(aSource, aDest);
}

/* static */
void
nsContentUtils::ASCIIToLower(const nsACString& aSource, nsACString& aDest) {
  return _ASCIIToLowerCopy<nsACString, char>(aSource, aDest);
}


template<typename StringType, typename CharType>
void
_ASCIIToUpperInSitu(StringType& aStr)
{
  CharType* iter = aStr.BeginWriting();
  CharType* end = aStr.EndWriting();
  MOZ_ASSERT(iter && end);

  while (iter != end) {
    CharType c = *iter;
    if (c >= 'a' && c <= 'z') {
      *iter = c + ('A' - 'a');
    }
    ++iter;
  }
}

/* static */
void
nsContentUtils::ASCIIToUpper(nsAString& aStr)
{
  return _ASCIIToUpperInSitu<nsAString, char16_t>(aStr);
}

/* static */
void
nsContentUtils::ASCIIToUpper(nsACString& aStr)
{
  return _ASCIIToUpperInSitu<nsACString, char>(aStr);
}

template<typename StringType, typename CharType>
void
_ASCIIToUpperCopy(const StringType& aSource, StringType& aDest)
{
  uint32_t len = aSource.Length();
  aDest.SetLength(len);
  MOZ_ASSERT(aDest.Length() == len);

  CharType* dest = aDest.BeginWriting();
  MOZ_ASSERT(dest);

  const CharType* iter = aSource.BeginReading();
  const CharType* end = aSource.EndReading();
  while (iter != end) {
    CharType c = *iter;
    *dest = (c >= 'a' && c <= 'z') ?
      c + ('A' - 'a') : c;
    ++iter;
    ++dest;
  }
}

/* static */
void
nsContentUtils::ASCIIToUpper(const nsAString& aSource, nsAString& aDest)
{
  return _ASCIIToUpperCopy<nsAString, char16_t>(aSource, aDest);
}

/* static */
void
nsContentUtils::ASCIIToUpper(const nsACString& aSource, nsACString& aDest)
{
  return _ASCIIToUpperCopy<nsACString, char>(aSource, aDest);
}

/* static */
bool
nsContentUtils::EqualsIgnoreASCIICase(const nsAString& aStr1,
                                      const nsAString& aStr2)
{
  uint32_t len = aStr1.Length();
  if (len != aStr2.Length()) {
    return false;
  }

  const char16_t* str1 = aStr1.BeginReading();
  const char16_t* str2 = aStr2.BeginReading();
  const char16_t* end = str1 + len;

  while (str1 < end) {
    char16_t c1 = *str1++;
    char16_t c2 = *str2++;

    // First check if any bits other than the 0x0020 differs
    if ((c1 ^ c2) & 0xffdf) {
      return false;
    }

    // We know they can only differ in the 0x0020 bit.
    // Likely the two chars are the same, so check that first
    if (c1 != c2) {
      // They do differ, but since it's only in the 0x0020 bit, check if it's
      // the same ascii char, but just differing in case
      char16_t c1Upper = c1 & 0xffdf;
      if (!('A' <= c1Upper && c1Upper <= 'Z')) {
        return false;
      }
    }
  }

  return true;
}

/* static */
bool
nsContentUtils::StringContainsASCIIUpper(const nsAString& aStr)
{
  const char16_t* iter = aStr.BeginReading();
  const char16_t* end = aStr.EndReading();
  while (iter != end) {
    char16_t c = *iter;
    if (c >= 'A' && c <= 'Z') {
      return true;
    }
    ++iter;
  }

  return false;
}

/* static */
nsIInterfaceRequestor*
nsContentUtils::SameOriginChecker()
{
  if (!sSameOriginChecker) {
    sSameOriginChecker = new SameOriginCheckerImpl();
    NS_ADDREF(sSameOriginChecker);
  }
  return sSameOriginChecker;
}

/* static */
nsresult
nsContentUtils::CheckSameOrigin(nsIChannel *aOldChannel, nsIChannel *aNewChannel)
{
  if (!nsContentUtils::GetSecurityManager())
    return NS_ERROR_NOT_AVAILABLE;

  nsCOMPtr<nsIPrincipal> oldPrincipal;
  nsContentUtils::GetSecurityManager()->
    GetChannelResultPrincipal(aOldChannel, getter_AddRefs(oldPrincipal));

  nsCOMPtr<nsIURI> newURI;
  aNewChannel->GetURI(getter_AddRefs(newURI));
  nsCOMPtr<nsIURI> newOriginalURI;
  aNewChannel->GetOriginalURI(getter_AddRefs(newOriginalURI));

  NS_ENSURE_STATE(oldPrincipal && newURI && newOriginalURI);

  nsresult rv = oldPrincipal->CheckMayLoad(newURI, false, false);
  if (NS_SUCCEEDED(rv) && newOriginalURI != newURI) {
    rv = oldPrincipal->CheckMayLoad(newOriginalURI, false, false);
  }

  return rv;
}

NS_IMPL_ISUPPORTS(SameOriginCheckerImpl,
                  nsIChannelEventSink,
                  nsIInterfaceRequestor)

NS_IMETHODIMP
SameOriginCheckerImpl::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
                                              nsIChannel* aNewChannel,
                                              uint32_t aFlags,
                                              nsIAsyncVerifyRedirectCallback* cb)
{
  NS_PRECONDITION(aNewChannel, "Redirecting to null channel?");

  nsresult rv = nsContentUtils::CheckSameOrigin(aOldChannel, aNewChannel);
  if (NS_SUCCEEDED(rv)) {
    cb->OnRedirectVerifyCallback(NS_OK);
  }

  return rv;
}

NS_IMETHODIMP
SameOriginCheckerImpl::GetInterface(const nsIID& aIID, void** aResult)
{
  return QueryInterface(aIID, aResult);
}

/* static */
nsresult
nsContentUtils::GetASCIIOrigin(nsIPrincipal* aPrincipal, nsACString& aOrigin)
{
  NS_PRECONDITION(aPrincipal, "missing principal");

  aOrigin.Truncate();

  nsCOMPtr<nsIURI> uri;
  nsresult rv = aPrincipal->GetURI(getter_AddRefs(uri));
  NS_ENSURE_SUCCESS(rv, rv);

  if (uri) {
    return GetASCIIOrigin(uri, aOrigin);
  }

  aOrigin.AssignLiteral("null");

  return NS_OK;
}

/* static */
nsresult
nsContentUtils::GetASCIIOrigin(nsIURI* aURI, nsACString& aOrigin)
{
  NS_PRECONDITION(aURI, "missing uri");

  // For Blob URI we have to return the origin of page using its principal.
  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(aURI);
  if (uriWithPrincipal) {
    nsCOMPtr<nsIPrincipal> principal;
    uriWithPrincipal->GetPrincipal(getter_AddRefs(principal));

    if (principal) {
      nsCOMPtr<nsIURI> uri;
      nsresult rv = principal->GetURI(getter_AddRefs(uri));
      NS_ENSURE_SUCCESS(rv, rv);

      if (uri && uri != aURI) {
        return GetASCIIOrigin(uri, aOrigin);
      }
    }
  }

  aOrigin.Truncate();

  nsCOMPtr<nsIURI> uri = NS_GetInnermostURI(aURI);
  NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);

  nsCString host;
  nsresult rv = uri->GetAsciiHost(host);

  if (NS_SUCCEEDED(rv) && !host.IsEmpty()) {
    nsCString scheme;
    rv = uri->GetScheme(scheme);
    NS_ENSURE_SUCCESS(rv, rv);

    int32_t port = -1;
    uri->GetPort(<