--- a/caps/moz.build
+++ b/caps/moz.build
@@ -36,16 +36,17 @@ EXPORTS.mozilla = [
 SOURCES += [
     # Compile this separately since nsExceptionHandler.h conflicts
     # with something from nsNullPrincipal.cpp.
     'BasePrincipal.cpp',
 ]
 
 UNIFIED_SOURCES += [
     'DomainPolicy.cpp',
+    'nsExpandedPrincipal.cpp',
     'nsJSPrincipals.cpp',
     'nsNullPrincipal.cpp',
     'nsNullPrincipalURI.cpp',
     'nsPrincipal.cpp',
     'nsScriptSecurityManager.cpp',
     'nsSystemPrincipal.cpp',
 ]
 

copy from caps/nsPrincipal.cpp
copy to caps/nsExpandedPrincipal.cpp
--- a/caps/nsPrincipal.cpp
+++ b/caps/nsExpandedPrincipal.cpp
@@ -1,471 +1,19 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=2 sw=2 et 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/. */
 
-#include "nsPrincipal.h"
-
-#include "mozIThirdPartyUtil.h"
-#include "nscore.h"
-#include "nsScriptSecurityManager.h"
-#include "nsString.h"
-#include "nsReadableUtils.h"
-#include "pratom.h"
-#include "nsIURI.h"
-#include "nsIURL.h"
-#include "nsIStandardURL.h"
-#include "nsIURIWithPrincipal.h"
-#include "nsJSPrincipals.h"
-#include "nsIEffectiveTLDService.h"
+#include "nsExpandedPrincipal.h"
 #include "nsIClassInfoImpl.h"
-#include "nsIProtocolHandler.h"
-#include "nsError.h"
-#include "nsIContentSecurityPolicy.h"
-#include "nsNetCID.h"
-#include "jswrapper.h"
-
-#include "mozilla/dom/nsCSPContext.h"
-#include "mozilla/dom/ScriptSettings.h"
-#include "mozilla/Preferences.h"
-#include "mozilla/HashFunctions.h"
 
 using namespace mozilla;
 
-static bool gCodeBasePrincipalSupport = false;
-
-static bool URIIsImmutable(nsIURI* aURI)
-{
-  nsCOMPtr<nsIMutable> mutableObj(do_QueryInterface(aURI));
-  bool isMutable;
-  return
-    mutableObj &&
-    NS_SUCCEEDED(mutableObj->GetMutable(&isMutable)) &&
-    !isMutable;
-}
-
-NS_IMPL_CLASSINFO(nsPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
-                  NS_PRINCIPAL_CID)
-NS_IMPL_QUERY_INTERFACE_CI(nsPrincipal,
-                           nsIPrincipal,
-                           nsISerializable)
-NS_IMPL_CI_INTERFACE_GETTER(nsPrincipal,
-                            nsIPrincipal,
-                            nsISerializable)
-
-// Called at startup:
-/* static */ void
-nsPrincipal::InitializeStatics()
-{
-  Preferences::AddBoolVarCache(&gCodeBasePrincipalSupport,
-                               "signed.applets.codebase_principal_support",
-                               false);
-}
-
-nsPrincipal::nsPrincipal()
-  : mCodebaseImmutable(false)
-  , mDomainImmutable(false)
-  , mInitialized(false)
-{ }
-
-nsPrincipal::~nsPrincipal()
-{
-  // let's clear the principal within the csp to avoid a tangling pointer
-  if (mCSP) {
-    static_cast<nsCSPContext*>(mCSP.get())->clearLoadingPrincipal();
-  }
-}
-
-nsresult
-nsPrincipal::Init(nsIURI *aCodebase, const OriginAttributes& aOriginAttributes)
-{
-  NS_ENSURE_STATE(!mInitialized);
-  NS_ENSURE_ARG(aCodebase);
-
-  mInitialized = true;
-
-  mCodebase = NS_TryToMakeImmutable(aCodebase);
-  mCodebaseImmutable = URIIsImmutable(mCodebase);
-  mOriginAttributes = aOriginAttributes;
-
-  return NS_OK;
-}
-
-nsresult
-nsPrincipal::GetScriptLocation(nsACString &aStr)
-{
-  return mCodebase->GetSpec(aStr);
-}
-
-nsresult
-nsPrincipal::GetOriginInternal(nsACString& aOrigin)
-{
-  if (!mCodebase) {
-    return NS_ERROR_FAILURE;
-  }
-
-  nsCOMPtr<nsIURI> origin = NS_GetInnermostURI(mCodebase);
-  if (!origin) {
-    return NS_ERROR_FAILURE;
-  }
-
-  nsAutoCString hostPort;
-
-  // chrome: URLs don't have a meaningful origin, so make
-  // sure we just get the full spec for them.
-  // XXX this should be removed in favor of the solution in
-  // bug 160042.
-  bool isChrome;
-  nsresult rv = origin->SchemeIs("chrome", &isChrome);
-  if (NS_SUCCEEDED(rv) && !isChrome) {
-    rv = origin->GetAsciiHostPort(hostPort);
-    // Some implementations return an empty string, treat it as no support
-    // for asciiHost by that implementation.
-    if (hostPort.IsEmpty()) {
-      rv = NS_ERROR_FAILURE;
-    }
-  }
-
-  // We want the invariant that prinA.origin == prinB.origin i.f.f.
-  // prinA.equals(prinB). However, this requires that we impose certain constraints
-  // on the behavior and origin semantics of principals, and in particular, forbid
-  // creating origin strings for principals whose equality constraints are not
-  // expressible as strings (i.e. object equality). Moreover, we want to forbid URIs
-  // containing the magic "^" we use as a separating character for origin
-  // attributes.
-  //
-  // These constraints can generally be achieved by restricting .origin to
-  // nsIStandardURL-based URIs, but there are a few other URI schemes that we need
-  // to handle.
-  bool isBehaved;
-  if ((NS_SUCCEEDED(origin->SchemeIs("about", &isBehaved)) && isBehaved) ||
-      (NS_SUCCEEDED(origin->SchemeIs("moz-safe-about", &isBehaved)) && isBehaved) ||
-      (NS_SUCCEEDED(origin->SchemeIs("indexeddb", &isBehaved)) && isBehaved)) {
-    rv = origin->GetAsciiSpec(aOrigin);
-    NS_ENSURE_SUCCESS(rv, rv);
-    // These URIs could technically contain a '^', but they never should.
-    if (NS_WARN_IF(aOrigin.FindChar('^', 0) != -1)) {
-      aOrigin.Truncate();
-      return NS_ERROR_FAILURE;
-    }
-    return NS_OK;
-  }
-
-  if (NS_SUCCEEDED(rv) && !isChrome) {
-    rv = origin->GetScheme(aOrigin);
-    NS_ENSURE_SUCCESS(rv, rv);
-    aOrigin.AppendLiteral("://");
-    aOrigin.Append(hostPort);
-    return NS_OK;
-  }
-
-  // This URL can be a blobURL. In this case, we should use the 'parent'
-  // principal instead.
-  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(origin);
-  if (uriWithPrincipal) {
-    nsCOMPtr<nsIPrincipal> uriPrincipal;
-    rv = uriWithPrincipal->GetPrincipal(getter_AddRefs(uriPrincipal));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    if (uriPrincipal) {
-      return uriPrincipal->GetOriginNoSuffix(aOrigin);
-    }
-  }
-
-  // If we reached this branch, we can only create an origin if we have a
-  // nsIStandardURL.  So, we query to a nsIStandardURL, and fail if we aren't
-  // an instance of an nsIStandardURL nsIStandardURLs have the good property
-  // of escaping the '^' character in their specs, which means that we can be
-  // sure that the caret character (which is reserved for delimiting the end
-  // of the spec, and the beginning of the origin attributes) is not present
-  // in the origin string
-  nsCOMPtr<nsIStandardURL> standardURL = do_QueryInterface(origin);
-  NS_ENSURE_TRUE(standardURL, NS_ERROR_FAILURE);
-
-  rv = origin->GetAsciiSpec(aOrigin);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  // The origin, when taken from the spec, should not contain the ref part of
-  // the URL.
-
-  int32_t pos = aOrigin.FindChar('?');
-  int32_t hashPos = aOrigin.FindChar('#');
-
-  if (hashPos != kNotFound && (pos == kNotFound || hashPos < pos)) {
-    pos = hashPos;
-  }
-
-  if (pos != kNotFound) {
-    aOrigin.Truncate(pos);
-  }
-
-  return NS_OK;
-}
-
-bool
-nsPrincipal::SubsumesInternal(nsIPrincipal* aOther,
-                              BasePrincipal::DocumentDomainConsideration aConsideration)
-{
-  MOZ_ASSERT(aOther);
-
-  // For nsPrincipal, Subsumes is equivalent to Equals.
-  if (aOther == this) {
-    return true;
-  }
-
-  // If either the subject or the object has changed its principal by
-  // explicitly setting document.domain then the other must also have
-  // done so in order to be considered the same origin. This prevents
-  // DNS spoofing based on document.domain (154930)
-  nsresult rv;
-  if (aConsideration == ConsiderDocumentDomain) {
-    // Get .domain on each principal.
-    nsCOMPtr<nsIURI> thisDomain, otherDomain;
-    GetDomain(getter_AddRefs(thisDomain));
-    aOther->GetDomain(getter_AddRefs(otherDomain));
-
-    // If either has .domain set, we have equality i.f.f. the domains match.
-    // Otherwise, we fall through to the non-document-domain-considering case.
-    if (thisDomain || otherDomain) {
-      return nsScriptSecurityManager::SecurityCompareURIs(thisDomain, otherDomain);
-    }
-  }
-
-  nsCOMPtr<nsIURI> otherURI;
-  rv = aOther->GetURI(getter_AddRefs(otherURI));
-  NS_ENSURE_SUCCESS(rv, false);
-
-  // Compare codebases.
-  return nsScriptSecurityManager::SecurityCompareURIs(mCodebase, otherURI);
-}
-
-NS_IMETHODIMP
-nsPrincipal::GetURI(nsIURI** aURI)
-{
-  if (mCodebaseImmutable) {
-    NS_ADDREF(*aURI = mCodebase);
-    return NS_OK;
-  }
-
-  if (!mCodebase) {
-    *aURI = nullptr;
-    return NS_OK;
-  }
-
-  return NS_EnsureSafeToReturn(mCodebase, aURI);
-}
-
-bool
-nsPrincipal::MayLoadInternal(nsIURI* aURI)
-{
-  // See if aURI is something like a Blob URI that is actually associated with
-  // a principal.
-  nsCOMPtr<nsIURIWithPrincipal> uriWithPrin = do_QueryInterface(aURI);
-  nsCOMPtr<nsIPrincipal> uriPrin;
-  if (uriWithPrin) {
-    uriWithPrin->GetPrincipal(getter_AddRefs(uriPrin));
-  }
-  if (uriPrin) {
-    return nsIPrincipal::Subsumes(uriPrin);
-  }
-
-  // If this principal is associated with an addon, check whether that addon
-  // has been given permission to load from this domain.
-  if (AddonAllowsLoad(aURI)) {
-    return true;
-  }
-
-  if (nsScriptSecurityManager::SecurityCompareURIs(mCodebase, aURI)) {
-    return true;
-  }
-
-  // If strict file origin policy is in effect, local files will always fail
-  // SecurityCompareURIs unless they are identical. Explicitly check file origin
-  // policy, in that case.
-  if (nsScriptSecurityManager::GetStrictFileOriginPolicy() &&
-      NS_URIIsLocalFile(aURI) &&
-      NS_RelaxStrictFileOriginPolicy(aURI, mCodebase)) {
-    return true;
-  }
-
-  return false;
-}
-
-void
-nsPrincipal::SetURI(nsIURI* aURI)
-{
-  mCodebase = NS_TryToMakeImmutable(aURI);
-  mCodebaseImmutable = URIIsImmutable(mCodebase);
-}
-
-NS_IMETHODIMP
-nsPrincipal::GetHashValue(uint32_t* aValue)
-{
-  NS_PRECONDITION(mCodebase, "Need a codebase");
-
-  *aValue = nsScriptSecurityManager::HashPrincipalByOrigin(this);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsPrincipal::GetDomain(nsIURI** aDomain)
-{
-  if (!mDomain) {
-    *aDomain = nullptr;
-    return NS_OK;
-  }
-
-  if (mDomainImmutable) {
-    NS_ADDREF(*aDomain = mDomain);
-    return NS_OK;
-  }
-
-  return NS_EnsureSafeToReturn(mDomain, aDomain);
-}
-
-NS_IMETHODIMP
-nsPrincipal::SetDomain(nsIURI* aDomain)
-{
-  mDomain = NS_TryToMakeImmutable(aDomain);
-  mDomainImmutable = URIIsImmutable(mDomain);
-
-  // Recompute all wrappers between compartments using this principal and other
-  // non-chrome compartments.
-  AutoSafeJSContext cx;
-  JSPrincipals *principals = nsJSPrincipals::get(static_cast<nsIPrincipal*>(this));
-  bool success = js::RecomputeWrappers(cx, js::ContentCompartmentsOnly(),
-                                       js::CompartmentsWithPrincipals(principals));
-  NS_ENSURE_TRUE(success, NS_ERROR_FAILURE);
-  success = js::RecomputeWrappers(cx, js::CompartmentsWithPrincipals(principals),
-                                  js::ContentCompartmentsOnly());
-  NS_ENSURE_TRUE(success, NS_ERROR_FAILURE);
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsPrincipal::GetBaseDomain(nsACString& aBaseDomain)
-{
-  // For a file URI, we return the file path.
-  if (NS_URIIsLocalFile(mCodebase)) {
-    nsCOMPtr<nsIURL> url = do_QueryInterface(mCodebase);
-
-    if (url) {
-      return url->GetFilePath(aBaseDomain);
-    }
-  }
-
-  bool hasNoRelativeFlag;
-  nsresult rv = NS_URIChainHasFlags(mCodebase,
-                                    nsIProtocolHandler::URI_NORELATIVE,
-                                    &hasNoRelativeFlag);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  if (hasNoRelativeFlag) {
-    return mCodebase->GetSpec(aBaseDomain);
-  }
-
-  // For everything else, we ask the TLD service via
-  // the ThirdPartyUtil.
-  nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
-    do_GetService(THIRDPARTYUTIL_CONTRACTID);
-  if (thirdPartyUtil) {
-    return thirdPartyUtil->GetBaseDomain(mCodebase, aBaseDomain);
-  }
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsPrincipal::Read(nsIObjectInputStream* aStream)
-{
-  nsCOMPtr<nsISupports> supports;
-  nsCOMPtr<nsIURI> codebase;
-  nsresult rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  codebase = do_QueryInterface(supports);
-
-  nsCOMPtr<nsIURI> domain;
-  rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  domain = do_QueryInterface(supports);
-
-  nsAutoCString suffix;
-  rv = aStream->ReadCString(suffix);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  OriginAttributes attrs;
-  bool ok = attrs.PopulateFromSuffix(suffix);
-  NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);
-
-  rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  rv = Init(codebase, attrs);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  mCSP = do_QueryInterface(supports, &rv);
-  // make sure setRequestContext is called after Init(),
-  // to make sure  the principals URI been initalized.
-  if (mCSP) {
-    mCSP->SetRequestContext(nullptr, this);
-  }
-
-  SetDomain(domain);
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsPrincipal::Write(nsIObjectOutputStream* aStream)
-{
-  NS_ENSURE_STATE(mCodebase);
-  nsresult rv = NS_WriteOptionalCompoundObject(aStream, mCodebase, NS_GET_IID(nsIURI),
-                                               true);
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  rv = NS_WriteOptionalCompoundObject(aStream, mDomain, NS_GET_IID(nsIURI),
-                                      true);
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  nsAutoCString suffix;
-  OriginAttributesRef().CreateSuffix(suffix);
-
-  rv = aStream->WriteStringZ(suffix.get());
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  rv = NS_WriteOptionalCompoundObject(aStream, mCSP,
-                                      NS_GET_IID(nsIContentSecurityPolicy),
-                                      true);
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  // mCodebaseImmutable and mDomainImmutable will be recomputed based
-  // on the deserialized URIs in Read().
-
-  return NS_OK;
-}
-
-/************************************************************************************************************************/
-
 NS_IMPL_CLASSINFO(nsExpandedPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
                   NS_EXPANDEDPRINCIPAL_CID)
 NS_IMPL_QUERY_INTERFACE_CI(nsExpandedPrincipal,
                            nsIPrincipal,
                            nsIExpandedPrincipal)
 NS_IMPL_CI_INTERFACE_GETTER(nsExpandedPrincipal,
                              nsIPrincipal,
                              nsIExpandedPrincipal)

copy from caps/nsPrincipal.h
copy to caps/nsExpandedPrincipal.h
--- a/caps/nsPrincipal.h
+++ b/caps/nsExpandedPrincipal.h
@@ -1,69 +1,24 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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/. */
 
-#ifndef nsPrincipal_h__
-#define nsPrincipal_h__
+#ifndef nsExpandedPrincipal_h
+#define nsExpandedPrincipal_h
 
 #include "nsCOMPtr.h"
 #include "nsJSPrincipals.h"
 #include "nsTArray.h"
-#include "nsIContentSecurityPolicy.h"
-#include "nsIProtocolHandler.h"
 #include "nsNetUtil.h"
-#include "nsScriptSecurityManager.h"
 #include "mozilla/BasePrincipal.h"
 
-class nsPrincipal final : public mozilla::BasePrincipal
-{
-public:
-  NS_DECL_NSISERIALIZABLE
-  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
-  NS_IMETHOD GetHashValue(uint32_t* aHashValue) override;
-  NS_IMETHOD GetURI(nsIURI** aURI) override;
-  NS_IMETHOD GetDomain(nsIURI** aDomain) override;
-  NS_IMETHOD SetDomain(nsIURI* aDomain) override;
-  NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
-  bool IsCodebasePrincipal() const override { return true; }
-  nsresult GetOriginInternal(nsACString& aOrigin) override;
-
-  nsPrincipal();
-
-  // Init() must be called before the principal is in a usable state.
-  nsresult Init(nsIURI* aCodebase,
-                const mozilla::OriginAttributes& aOriginAttributes);
-
-  virtual nsresult GetScriptLocation(nsACString& aStr) override;
-  void SetURI(nsIURI* aURI);
-
-  /**
-   * Called at startup to setup static data, e.g. about:config pref-observers.
-   */
-  static void InitializeStatics();
-
-  PrincipalKind Kind() override { return eCodebasePrincipal; }
-
-  nsCOMPtr<nsIURI> mDomain;
-  nsCOMPtr<nsIURI> mCodebase;
-  // If mCodebaseImmutable is true, mCodebase is non-null and immutable
-  bool mCodebaseImmutable;
-  bool mDomainImmutable;
-  bool mInitialized;
-
-protected:
-  virtual ~nsPrincipal();
-
-  bool SubsumesInternal(nsIPrincipal* aOther, DocumentDomainConsideration aConsideration) override;
-  bool MayLoadInternal(nsIURI* aURI) override;
-};
-
-class nsExpandedPrincipal : public nsIExpandedPrincipal, public mozilla::BasePrincipal
+class nsExpandedPrincipal : public nsIExpandedPrincipal
+                          , public mozilla::BasePrincipal
 {
 public:
   nsExpandedPrincipal(nsTArray<nsCOMPtr<nsIPrincipal>> &aWhiteList,
                       const mozilla::OriginAttributes& aAttrs);
 
   NS_DECL_NSIEXPANDEDPRINCIPAL
   NS_DECL_NSISERIALIZABLE
   NS_IMETHOD_(MozExternalRefCountType) AddRef() override { return nsJSPrincipals::AddRef(); };
@@ -85,19 +40,14 @@ protected:
 
   bool SubsumesInternal(nsIPrincipal* aOther, DocumentDomainConsideration aConsideration) override;
   bool MayLoadInternal(nsIURI* aURI) override;
 
 private:
   nsTArray< nsCOMPtr<nsIPrincipal> > mPrincipals;
 };
 
-#define NS_PRINCIPAL_CONTRACTID "@mozilla.org/principal;1"
-#define NS_PRINCIPAL_CID \
-{ 0x653e0e4d, 0x3ee4, 0x45fa, \
-  { 0xb2, 0x72, 0x97, 0xc2, 0x0b, 0xc0, 0x1e, 0xb8 } }
-
 #define NS_EXPANDEDPRINCIPAL_CONTRACTID "@mozilla.org/expandedprincipal;1"
 #define NS_EXPANDEDPRINCIPAL_CID \
 { 0xe8ee88b0, 0x5571, 0x4086, \
   { 0xa4, 0x5b, 0x39, 0xa7, 0x16, 0x90, 0x6b, 0xdb } }
 
-#endif // nsPrincipal_h__
+#endif // nsExpandedPrincipal_h

--- a/caps/nsIPrincipal.idl
+++ b/caps/nsIPrincipal.idl
@@ -6,19 +6,39 @@
 /* Defines the abstract interface for a principal. */
 
 #include "nsISerializable.idl"
 
 %{C++
 struct JSPrincipals;
 #include "nsCOMPtr.h"
 #include "nsTArray.h"
+#include "mozilla/DebugOnly.h"
 namespace mozilla {
 class OriginAttributes;
 }
+
+/**
+ * Some methods have a fast path for the case when we're comparing a principal
+ * to itself. The situation may happen for example with about:blank documents.
+ */
+
+#define DECL_FAST_INLINE_HELPER(method_)                       \
+  inline bool method_(nsIPrincipal* aOther)                    \
+  {                                                            \
+    mozilla::DebugOnly<bool> val = false;                      \
+    MOZ_ASSERT_IF(this == aOther,                              \
+                  NS_SUCCEEDED(method_(aOther, &val)) && val); \
+                                                               \
+    bool retVal = false;                                       \
+    return                                                     \
+      this == aOther ||                                        \
+      (NS_SUCCEEDED(method_(aOther, &retVal)) && retVal);      \
+  }
+
 %}
 
 interface nsIURI;
 interface nsIContentSecurityPolicy;
 interface nsIDOMDocument;
 
 [ptr] native JSContext(JSContext);
 [ptr] native JSPrincipals(JSPrincipals);
@@ -36,25 +56,18 @@ interface nsIPrincipal : nsISerializable
     boolean equals(in nsIPrincipal other);
 
     /**
      * Like equals, but takes document.domain changes into account.
      */
     boolean equalsConsideringDomain(in nsIPrincipal other);
 
     %{C++
-    inline bool Equals(nsIPrincipal* aOther) {
-      bool equal = false;
-      return NS_SUCCEEDED(Equals(aOther, &equal)) && equal;
-    }
-
-    inline bool EqualsConsideringDomain(nsIPrincipal* aOther) {
-      bool equal = false;
-      return NS_SUCCEEDED(EqualsConsideringDomain(aOther, &equal)) && equal;
-    }
+      DECL_FAST_INLINE_HELPER(Equals)
+      DECL_FAST_INLINE_HELPER(EqualsConsideringDomain)
     %}
 
     /**
      * Returns a hash value for the principal.
      */
     [noscript] readonly attribute unsigned long hashValue;
 
     /**
@@ -96,30 +109,20 @@ interface nsIPrincipal : nsISerializable
 
     /**
      * Same as the subsumesConsideringDomain(), but ignores the first party
      * domain in its originAttributes.
      */
     boolean subsumesConsideringDomainIgnoringFPD(in nsIPrincipal other);
 
     %{C++
-    inline bool Subsumes(nsIPrincipal* aOther) {
-      bool subsumes = false;
-      return NS_SUCCEEDED(Subsumes(aOther, &subsumes)) && subsumes;
-    }
-
-    inline bool SubsumesConsideringDomain(nsIPrincipal* aOther) {
-      bool subsumes = false;
-      return NS_SUCCEEDED(SubsumesConsideringDomain(aOther, &subsumes)) && subsumes;
-    }
-
-    inline bool SubsumesConsideringDomainIgnoringFPD(nsIPrincipal* aOther) {
-      bool subsumes = false;
-      return NS_SUCCEEDED(SubsumesConsideringDomainIgnoringFPD(aOther, &subsumes)) && subsumes;
-    }
+      DECL_FAST_INLINE_HELPER(Subsumes)
+      DECL_FAST_INLINE_HELPER(SubsumesConsideringDomain)
+      DECL_FAST_INLINE_HELPER(SubsumesConsideringDomainIgnoringFPD)
+#undef DECL_FAST_INLINE_HELPER
     %}
 
     /**
      * Checks whether this principal is allowed to load the network resource
      * located at the given URI under the same-origin policy. This means that
      * codebase principals are only allowed to load resources from the same
      * domain, the system principal is allowed to load anything, and null
      * principals can only load URIs where they are the principal. This is

--- a/caps/nsPrincipal.cpp
+++ b/caps/nsPrincipal.cpp
@@ -453,208 +453,8 @@ nsPrincipal::Write(nsIObjectOutputStream
     return rv;
   }
 
   // mCodebaseImmutable and mDomainImmutable will be recomputed based
   // on the deserialized URIs in Read().
 
   return NS_OK;
 }
-
-/************************************************************************************************************************/
-
-NS_IMPL_CLASSINFO(nsExpandedPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
-                  NS_EXPANDEDPRINCIPAL_CID)
-NS_IMPL_QUERY_INTERFACE_CI(nsExpandedPrincipal,
-                           nsIPrincipal,
-                           nsIExpandedPrincipal)
-NS_IMPL_CI_INTERFACE_GETTER(nsExpandedPrincipal,
-                             nsIPrincipal,
-                             nsIExpandedPrincipal)
-
-struct OriginComparator
-{
-  bool LessThan(nsIPrincipal* a, nsIPrincipal* b) const
-  {
-    nsAutoCString originA;
-    nsresult rv = a->GetOrigin(originA);
-    NS_ENSURE_SUCCESS(rv, false);
-    nsAutoCString originB;
-    rv = b->GetOrigin(originB);
-    NS_ENSURE_SUCCESS(rv, false);
-    return originA < originB;
-  }
-
-  bool Equals(nsIPrincipal* a, nsIPrincipal* b) const
-  {
-    nsAutoCString originA;
-    nsresult rv = a->GetOrigin(originA);
-    NS_ENSURE_SUCCESS(rv, false);
-    nsAutoCString originB;
-    rv = b->GetOrigin(originB);
-    NS_ENSURE_SUCCESS(rv, false);
-    return a == b;
-  }
-};
-
-nsExpandedPrincipal::nsExpandedPrincipal(nsTArray<nsCOMPtr<nsIPrincipal>> &aWhiteList,
-                                         const OriginAttributes& aAttrs)
-{
-  // We force the principals to be sorted by origin so that nsExpandedPrincipal
-  // origins can have a canonical form.
-  OriginComparator c;
-  for (size_t i = 0; i < aWhiteList.Length(); ++i) {
-    mPrincipals.InsertElementSorted(aWhiteList[i], c);
-  }
-  mOriginAttributes = aAttrs;
-}
-
-nsExpandedPrincipal::~nsExpandedPrincipal()
-{ }
-
-NS_IMETHODIMP
-nsExpandedPrincipal::GetDomain(nsIURI** aDomain)
-{
-  *aDomain = nullptr;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::SetDomain(nsIURI* aDomain)
-{
-  return NS_OK;
-}
-
-nsresult
-nsExpandedPrincipal::GetOriginInternal(nsACString& aOrigin)
-{
-  aOrigin.AssignLiteral("[Expanded Principal [");
-  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
-    if (i != 0) {
-      aOrigin.AppendLiteral(", ");
-    }
-
-    nsAutoCString subOrigin;
-    nsresult rv = mPrincipals.ElementAt(i)->GetOrigin(subOrigin);
-    NS_ENSURE_SUCCESS(rv, rv);
-    aOrigin.Append(subOrigin);
-  }
-
-  aOrigin.Append("]]");
-  return NS_OK;
-}
-
-bool
-nsExpandedPrincipal::SubsumesInternal(nsIPrincipal* aOther,
-                                      BasePrincipal::DocumentDomainConsideration aConsideration)
-{
-  // If aOther is an ExpandedPrincipal too, we break it down into its component
-  // nsIPrincipals, and check subsumes on each one.
-  nsCOMPtr<nsIExpandedPrincipal> expanded = do_QueryInterface(aOther);
-  if (expanded) {
-    nsTArray< nsCOMPtr<nsIPrincipal> >* otherList;
-    expanded->GetWhiteList(&otherList);
-    for (uint32_t i = 0; i < otherList->Length(); ++i){
-      // Use SubsumesInternal rather than Subsumes here, since OriginAttribute
-      // checks are only done between non-expanded sub-principals, and we don't
-      // need to incur the extra virtual call overhead.
-      if (!SubsumesInternal((*otherList)[i], aConsideration)) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  // We're dealing with a regular principal. One of our principals must subsume
-  // it.
-  for (uint32_t i = 0; i < mPrincipals.Length(); ++i) {
-    if (Cast(mPrincipals[i])->Subsumes(aOther, aConsideration)) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-bool
-nsExpandedPrincipal::MayLoadInternal(nsIURI* uri)
-{
-  for (uint32_t i = 0; i < mPrincipals.Length(); ++i){
-    if (BasePrincipal::Cast(mPrincipals[i])->MayLoadInternal(uri)) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::GetHashValue(uint32_t* result)
-{
-  MOZ_CRASH("extended principal should never be used as key in a hash map");
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::GetURI(nsIURI** aURI)
-{
-  *aURI = nullptr;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::GetWhiteList(nsTArray<nsCOMPtr<nsIPrincipal> >** aWhiteList)
-{
-  *aWhiteList = &mPrincipals;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::GetBaseDomain(nsACString& aBaseDomain)
-{
-  return NS_ERROR_NOT_AVAILABLE;
-}
-
-bool
-nsExpandedPrincipal::AddonHasPermission(const nsAString& aPerm)
-{
-  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
-    if (BasePrincipal::Cast(mPrincipals[i])->AddonHasPermission(aPerm)) {
-      return true;
-    }
-  }
-  return false;
-}
-
-nsresult
-nsExpandedPrincipal::GetScriptLocation(nsACString& aStr)
-{
-  aStr.Assign("[Expanded Principal [");
-  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
-    if (i != 0) {
-      aStr.AppendLiteral(", ");
-    }
-
-    nsAutoCString spec;
-    nsresult rv =
-      nsJSPrincipals::get(mPrincipals.ElementAt(i))->GetScriptLocation(spec);
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    aStr.Append(spec);
-  }
-  aStr.Append("]]");
-  return NS_OK;
-}
-
-//////////////////////////////////////////
-// Methods implementing nsISerializable //
-//////////////////////////////////////////
-
-NS_IMETHODIMP
-nsExpandedPrincipal::Read(nsIObjectInputStream* aStream)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-nsExpandedPrincipal::Write(nsIObjectOutputStream* aStream)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}

--- a/caps/nsPrincipal.h
+++ b/caps/nsPrincipal.h
@@ -53,51 +53,14 @@ public:
 
 protected:
   virtual ~nsPrincipal();
 
   bool SubsumesInternal(nsIPrincipal* aOther, DocumentDomainConsideration aConsideration) override;
   bool MayLoadInternal(nsIURI* aURI) override;
 };
 
-class nsExpandedPrincipal : public nsIExpandedPrincipal, public mozilla::BasePrincipal
-{
-public:
-  nsExpandedPrincipal(nsTArray<nsCOMPtr<nsIPrincipal>> &aWhiteList,
-                      const mozilla::OriginAttributes& aAttrs);
-
-  NS_DECL_NSIEXPANDEDPRINCIPAL
-  NS_DECL_NSISERIALIZABLE
-  NS_IMETHOD_(MozExternalRefCountType) AddRef() override { return nsJSPrincipals::AddRef(); };
-  NS_IMETHOD_(MozExternalRefCountType) Release() override { return nsJSPrincipals::Release(); };
-  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
-  NS_IMETHOD GetHashValue(uint32_t* aHashValue) override;
-  NS_IMETHOD GetURI(nsIURI** aURI) override;
-  NS_IMETHOD GetDomain(nsIURI** aDomain) override;
-  NS_IMETHOD SetDomain(nsIURI* aDomain) override;
-  NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
-  virtual bool AddonHasPermission(const nsAString& aPerm) override;
-  virtual nsresult GetScriptLocation(nsACString &aStr) override;
-  nsresult GetOriginInternal(nsACString& aOrigin) override;
-
-  PrincipalKind Kind() override { return eExpandedPrincipal; }
-
-protected:
-  virtual ~nsExpandedPrincipal();
-
-  bool SubsumesInternal(nsIPrincipal* aOther, DocumentDomainConsideration aConsideration) override;
-  bool MayLoadInternal(nsIURI* aURI) override;
-
-private:
-  nsTArray< nsCOMPtr<nsIPrincipal> > mPrincipals;
-};
-
 #define NS_PRINCIPAL_CONTRACTID "@mozilla.org/principal;1"
 #define NS_PRINCIPAL_CID \
 { 0x653e0e4d, 0x3ee4, 0x45fa, \
   { 0xb2, 0x72, 0x97, 0xc2, 0x0b, 0xc0, 0x1e, 0xb8 } }
 
-#define NS_EXPANDEDPRINCIPAL_CONTRACTID "@mozilla.org/expandedprincipal;1"
-#define NS_EXPANDEDPRINCIPAL_CID \
-{ 0xe8ee88b0, 0x5571, 0x4086, \
-  { 0xa4, 0x5b, 0x39, 0xa7, 0x16, 0x90, 0x6b, 0xdb } }
-
 #endif // nsPrincipal_h__

--- a/devtools/client/framework/test/shared-head.js
+++ b/devtools/client/framework/test/shared-head.js
@@ -107,26 +107,28 @@ registerCleanupFunction(function* cleanu
 
 /**
  * Add a new test tab in the browser and load the given url.
  * @param {String} url The url to be loaded in the new tab
  * @param {Object} options Object with various optional fields:
  *   - {Boolean} background If true, open the tab in background
  *   - {ChromeWindow} window Firefox top level window we should use to open the tab
  *   - {Number} userContextId The userContextId of the tab.
+ *   - {String} preferredRemoteType
  * @return a promise that resolves to the tab object when the url is loaded
  */
 var addTab = Task.async(function* (url, options = { background: false, window: window }) {
   info("Adding a new tab with URL: " + url);
 
   let { background } = options;
   let { gBrowser } = options.window ? options.window : window;
   let { userContextId } = options;
 
-  let tab = gBrowser.addTab(url, {userContextId});
+  let tab = gBrowser.addTab(url,
+    {userContextId, preferredRemoteType: options.preferredRemoteType});
   if (!background) {
     gBrowser.selectedTab = tab;
   }
   yield BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
   info("Tab added and finished loading");
 
   return tab;

--- a/devtools/client/webconsole/test/head.js
+++ b/devtools/client/webconsole/test/head.js
@@ -42,44 +42,27 @@ var WCUL10n = new WebConsoleUtils.L10n(W
 
 const DOCS_GA_PARAMS = "?utm_source=mozilla" +
                        "&utm_medium=firefox-console-errors" +
                        "&utm_campaign=default";
 
 flags.testing = true;
 
 function loadTab(url, preferredRemoteType) {
-  let deferred = promise.defer();
-
-  let tab = gBrowser.selectedTab = gBrowser.addTab(url, { preferredRemoteType });
-  let browser = gBrowser.getBrowserForTab(tab);
-
-  browser.addEventListener("load", function () {
-    deferred.resolve({tab: tab, browser: browser});
-  }, {capture: true, once: true});
-
-  return deferred.promise;
+  return addTab(url, { preferredRemoteType }).then( tab => {
+    return { tab, browser: tab.linkedBrowser };
+  });
 }
 
 function loadBrowser(browser) {
   return BrowserTestUtils.browserLoaded(browser);
 }
 
 function closeTab(tab) {
-  let deferred = promise.defer();
-
-  let container = gBrowser.tabContainer;
-
-  container.addEventListener("TabClose", function () {
-    deferred.resolve(null);
-  }, {capture: true, once: true});
-
-  gBrowser.removeTab(tab);
-
-  return deferred.promise;
+  return removeTab(tab);
 }
 
 /**
  * Load the page and return the associated HUD.
  *
  * @param string uri
  *   The URI of the page to load.
  * @param string consoleType [optional]

--- a/docshell/base/LoadContext.cpp
+++ b/docshell/base/LoadContext.cpp
@@ -41,27 +41,29 @@ namespace mozilla {
 NS_IMPL_ISUPPORTS(LoadContext, nsILoadContext, nsIInterfaceRequestor)
 
 LoadContext::LoadContext(nsIPrincipal* aPrincipal,
                          nsILoadContext* aOptionalBase)
   : mTopFrameElement(nullptr)
   , mNestedFrameId(0)
   , mIsContent(true)
   , mUseRemoteTabs(false)
+  , mUseTrackingProtection(false)
 #ifdef DEBUG
   , mIsNotNull(true)
 #endif
 {
   mOriginAttributes.Inherit(aPrincipal->OriginAttributesRef());
   if (!aOptionalBase) {
     return;
   }
 
   MOZ_ALWAYS_SUCCEEDS(aOptionalBase->GetIsContent(&mIsContent));
   MOZ_ALWAYS_SUCCEEDS(aOptionalBase->GetUseRemoteTabs(&mUseRemoteTabs));
+  MOZ_ALWAYS_SUCCEEDS(aOptionalBase->GetUseTrackingProtection(&mUseTrackingProtection));
 }
 
 //-----------------------------------------------------------------------------
 // LoadContext::nsILoadContext
 //-----------------------------------------------------------------------------
 
 NS_IMETHODIMP
 LoadContext::GetAssociatedWindow(mozIDOMWindowProxy**)
@@ -175,30 +177,32 @@ LoadContext::GetOriginAttributes(JS::Mut
   MOZ_ASSERT(cx);
 
   bool ok = ToJSValue(cx, mOriginAttributes, aAttrs);
   NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);
   return NS_OK;
 }
 
 NS_IMETHODIMP
-LoadContext::IsTrackingProtectionOn(bool* aIsTrackingProtectionOn)
+LoadContext::GetUseTrackingProtection(bool* aUseTrackingProtection)
 {
   MOZ_ASSERT(mIsNotNull);
 
-  if (Preferences::GetBool("privacy.trackingprotection.enabled", false)) {
-    *aIsTrackingProtectionOn = true;
-  } else if ((mOriginAttributes.mPrivateBrowsingId > 0) &&
-             Preferences::GetBool("privacy.trackingprotection.pbmode.enabled", false)) {
-    *aIsTrackingProtectionOn = true;
-  } else {
-    *aIsTrackingProtectionOn = false;
-  }
+  NS_ENSURE_ARG_POINTER(aUseTrackingProtection);
+
+  *aUseTrackingProtection = mUseTrackingProtection;
+  return NS_OK;
+}
 
-  return NS_OK;
+NS_IMETHODIMP
+LoadContext::SetUseTrackingProtection(bool aUseTrackingProtection)
+{
+  MOZ_ASSERT_UNREACHABLE("Should only be set through nsDocShell");
+
+  return NS_ERROR_UNEXPECTED;
 }
 
 //-----------------------------------------------------------------------------
 // LoadContext::nsIInterfaceRequestor
 //-----------------------------------------------------------------------------
 NS_IMETHODIMP
 LoadContext::GetInterface(const nsIID& aIID, void** aResult)
 {

--- a/docshell/base/LoadContext.h
+++ b/docshell/base/LoadContext.h
@@ -40,62 +40,67 @@ public:
   // provided by child process.
   LoadContext(const IPC::SerializedLoadContext& aToCopy,
               dom::Element* aTopFrameElement,
               OriginAttributes& aAttrs)
     : mTopFrameElement(do_GetWeakReference(aTopFrameElement))
     , mNestedFrameId(0)
     , mIsContent(aToCopy.mIsContent)
     , mUseRemoteTabs(aToCopy.mUseRemoteTabs)
+    , mUseTrackingProtection(aToCopy.mUseTrackingProtection)
     , mOriginAttributes(aAttrs)
 #ifdef DEBUG
     , mIsNotNull(aToCopy.mIsNotNull)
 #endif
   {
   }
 
   // appId/inIsolatedMozBrowser arguments override those in SerializedLoadContext
   // provided by child process.
   LoadContext(const IPC::SerializedLoadContext& aToCopy,
               uint64_t aNestedFrameId,
               OriginAttributes& aAttrs)
     : mTopFrameElement(nullptr)
     , mNestedFrameId(aNestedFrameId)
     , mIsContent(aToCopy.mIsContent)
     , mUseRemoteTabs(aToCopy.mUseRemoteTabs)
+    , mUseTrackingProtection(aToCopy.mUseTrackingProtection)
     , mOriginAttributes(aAttrs)
 #ifdef DEBUG
     , mIsNotNull(aToCopy.mIsNotNull)
 #endif
   {
   }
 
   LoadContext(dom::Element* aTopFrameElement,
               bool aIsContent,
               bool aUsePrivateBrowsing,
               bool aUseRemoteTabs,
+              bool aUseTrackingProtection,
               const OriginAttributes& aAttrs)
     : mTopFrameElement(do_GetWeakReference(aTopFrameElement))
     , mNestedFrameId(0)
     , mIsContent(aIsContent)
     , mUseRemoteTabs(aUseRemoteTabs)
+    , mUseTrackingProtection(aUseTrackingProtection)
     , mOriginAttributes(aAttrs)
 #ifdef DEBUG
     , mIsNotNull(true)
 #endif
   {
     MOZ_DIAGNOSTIC_ASSERT(aUsePrivateBrowsing == (aAttrs.mPrivateBrowsingId > 0));
   }
 
   // Constructor taking reserved origin attributes.
   explicit LoadContext(OriginAttributes& aAttrs)
     : mTopFrameElement(nullptr)
     , mNestedFrameId(0)
     , mIsContent(false)
     , mUseRemoteTabs(false)
+    , mUseTrackingProtection(false)
     , mOriginAttributes(aAttrs)
 #ifdef DEBUG
     , mIsNotNull(true)
 #endif
   {
   }
 
   // Constructor for creating a LoadContext with a given principal's appId and
@@ -105,16 +110,17 @@ public:
 
 private:
   ~LoadContext() {}
 
   nsWeakPtr mTopFrameElement;
   uint64_t mNestedFrameId;
   bool mIsContent;
   bool mUseRemoteTabs;
+  bool mUseTrackingProtection;
   OriginAttributes mOriginAttributes;
 #ifdef DEBUG
   bool mIsNotNull;
 #endif
 };
 
 } // namespace mozilla
 

--- a/docshell/base/SerializedLoadContext.cpp
+++ b/docshell/base/SerializedLoadContext.cpp
@@ -56,22 +56,24 @@ SerializedLoadContext::SerializedLoadCon
 void
 SerializedLoadContext::Init(nsILoadContext* aLoadContext)
 {
   if (aLoadContext) {
     mIsNotNull = true;
     mIsPrivateBitValid = true;
     aLoadContext->GetIsContent(&mIsContent);
     aLoadContext->GetUseRemoteTabs(&mUseRemoteTabs);
+    aLoadContext->GetUseTrackingProtection(&mUseTrackingProtection);
     if (!aLoadContext->GetOriginAttributes(mOriginAttributes)) {
       NS_WARNING("GetOriginAttributes failed");
     }
   } else {
     mIsNotNull = false;
     mIsPrivateBitValid = false;
     // none of below values really matter when mIsNotNull == false:
     // we won't be GetInterfaced to nsILoadContext
     mIsContent = true;
     mUseRemoteTabs = false;
+    mUseTrackingProtection = false;
   }
 }
 
 } // namespace IPC

--- a/docshell/base/SerializedLoadContext.h
+++ b/docshell/base/SerializedLoadContext.h
@@ -27,16 +27,17 @@ namespace IPC {
 class SerializedLoadContext
 {
 public:
   SerializedLoadContext()
     : mIsNotNull(false)
     , mIsPrivateBitValid(false)
     , mIsContent(false)
     , mUseRemoteTabs(false)
+    , mUseTrackingProtection(false)
   {
     Init(nullptr);
   }
 
   explicit SerializedLoadContext(nsILoadContext* aLoadContext);
   explicit SerializedLoadContext(nsIChannel* aChannel);
   explicit SerializedLoadContext(nsIWebSocketChannel* aChannel);
 
@@ -47,16 +48,17 @@ public:
 
   // used to indicate if child-side LoadContext * was null.
   bool mIsNotNull;
   // used to indicate if child-side mUsePrivateBrowsing flag is valid, even if
   // mIsNotNull is false, i.e., child LoadContext was null.
   bool mIsPrivateBitValid;
   bool mIsContent;
   bool mUseRemoteTabs;
+  bool mUseTrackingProtection;
   mozilla::OriginAttributes mOriginAttributes;
 };
 
 // Function to serialize over IPDL
 template<>
 struct ParamTraits<SerializedLoadContext>
 {
   typedef SerializedLoadContext paramType;
@@ -65,26 +67,28 @@ struct ParamTraits<SerializedLoadContext
   {
     nsAutoCString suffix;
     aParam.mOriginAttributes.CreateSuffix(suffix);
 
     WriteParam(aMsg, aParam.mIsNotNull);
     WriteParam(aMsg, aParam.mIsContent);
     WriteParam(aMsg, aParam.mIsPrivateBitValid);
     WriteParam(aMsg, aParam.mUseRemoteTabs);
+    WriteParam(aMsg, aParam.mUseTrackingProtection);
     WriteParam(aMsg, suffix);
   }
 
   static bool Read(const Message* aMsg, PickleIterator* aIter, paramType* aResult)
   {
     nsAutoCString suffix;
     if (!ReadParam(aMsg, aIter, &aResult->mIsNotNull) ||
         !ReadParam(aMsg, aIter, &aResult->mIsContent) ||
         !ReadParam(aMsg, aIter, &aResult->mIsPrivateBitValid) ||
         !ReadParam(aMsg, aIter, &aResult->mUseRemoteTabs) ||
+        !ReadParam(aMsg, aIter, &aResult->mUseTrackingProtection) ||
         !ReadParam(aMsg, aIter, &suffix)) {
       return false;
     }
     return aResult->mOriginAttributes.PopulateFromSuffix(suffix);
   }
 };
 
 } // namespace IPC

--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -790,16 +790,17 @@ nsDocShell::nsDocShell()
   , mAllowKeywordFixup(false)
   , mIsOffScreenBrowser(false)
   , mIsActive(true)
   , mDisableMetaRefreshWhenInactive(false)
   , mIsPrerendered(false)
   , mIsAppTab(false)
   , mUseGlobalHistory(false)
   , mUseRemoteTabs(false)
+  , mUseTrackingProtection(false)
   , mDeviceSizeIsPageSize(false)
   , mWindowDraggingAllowed(false)
   , mInFrameSwap(false)
   , mInheritPrivateBrowsingId(true)
   , mCanExecuteScripts(false)
   , mFiredUnloadEvent(false)
   , mEODForCurrentDocument(false)
   , mURIResultedInDocument(false)
@@ -8847,24 +8848,17 @@ nsDocShell::RestoreFromHistory()
 
   nsCOMPtr<nsIDocument> document = do_QueryInterface(domDoc);
   if (document) {
     RefPtr<nsDocShell> parent = GetParentDocshell();
     if (parent) {
       nsCOMPtr<nsIDocument> d = parent->GetDocument();
       if (d) {
         if (d->EventHandlingSuppressed()) {
-          document->SuppressEventHandling(nsIDocument::eEvents,
-                                          d->EventHandlingSuppressed());
-        }
-
-        // Ick, it'd be nicer to not rewalk all of the subdocs here.
-        if (d->AnimationsPaused()) {
-          document->SuppressEventHandling(nsIDocument::eAnimationsOnly,
-                                          d->AnimationsPaused());
+          document->SuppressEventHandling(d->EventHandlingSuppressed());
         }
       }
     }
 
     // Use the uri from the mLSHE we had when we entered this function
     // (which need not match the document's URI if anchors are involved),
     // since that's the history entry we're loading.  Note that if we use
     // origLSHE we don't have to worry about whether the entry in question
@@ -13681,27 +13675,50 @@ nsDocShell::GetTopFrameElement(nsIDOMEle
 NS_IMETHODIMP
 nsDocShell::GetNestedFrameId(uint64_t* aId)
 {
   *aId = 0;
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsDocShell::IsTrackingProtectionOn(bool* aIsTrackingProtectionOn)
-{
-  if (Preferences::GetBool("privacy.trackingprotection.enabled", false)) {
-    *aIsTrackingProtectionOn = true;
-  } else if (UsePrivateBrowsing() &&
-             Preferences::GetBool("privacy.trackingprotection.pbmode.enabled", false)) {
-    *aIsTrackingProtectionOn = true;
-  } else {
-    *aIsTrackingProtectionOn = false;
-  }
-
+nsDocShell::GetUseTrackingProtection(bool* aUseTrackingProtection)
+{
+  *aUseTrackingProtection  = false;
+
+  static bool sTPEnabled = false;
+  static bool sTPInPBEnabled = false;
+  static bool sPrefsInit = false;
+
+  if (!sPrefsInit) {
+    sPrefsInit = true;
+    Preferences::AddBoolVarCache(&sTPEnabled,
+      "privacy.trackingprotection.enabled", false);
+    Preferences::AddBoolVarCache(&sTPInPBEnabled,
+      "privacy.trackingprotection.pbmode.enabled", false);
+  }
+
+  if (mUseTrackingProtection || sTPEnabled ||
+      (UsePrivateBrowsing() && sTPInPBEnabled)) {
+    *aUseTrackingProtection = true;
+    return NS_OK;
+  }
+
+  RefPtr<nsDocShell> parent = GetParentDocshell();
+  if (parent) {
+    return parent->GetUseTrackingProtection(aUseTrackingProtection);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetUseTrackingProtection(bool aUseTrackingProtection)
+{
+  mUseTrackingProtection = aUseTrackingProtection;
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDocShell::GetIsContent(bool* aIsContent)
 {
   *aIsContent = (mItemType == typeContent);
   return NS_OK;

--- a/docshell/base/nsDocShell.h
+++ b/docshell/base/nsDocShell.h
@@ -229,17 +229,16 @@ public:
   NS_IMETHOD GetNestedFrameId(uint64_t*) override;
   NS_IMETHOD GetIsContent(bool*) override;
   NS_IMETHOD GetUsePrivateBrowsing(bool*) override;
   NS_IMETHOD SetUsePrivateBrowsing(bool) override;
   NS_IMETHOD SetPrivateBrowsing(bool) override;
   NS_IMETHOD GetUseRemoteTabs(bool*) override;
   NS_IMETHOD SetRemoteTabs(bool) override;
   NS_IMETHOD GetOriginAttributes(JS::MutableHandle<JS::Value>) override;
-  NS_IMETHOD IsTrackingProtectionOn(bool*) override;
 
   // Restores a cached presentation from history (mLSHE).
   // This method swaps out the content viewer and simulates loads for
   // subframes. It then simulates the completion of the toplevel load.
   nsresult RestoreFromHistory();
 
   // Perform a URI load from a refresh timer. This is just like the
   // ForceRefreshURI method on nsIRefreshURI, but makes sure to take
@@ -956,16 +955,17 @@ protected:
   bool mAllowKeywordFixup : 1;
   bool mIsOffScreenBrowser : 1;
   bool mIsActive : 1;
   bool mDisableMetaRefreshWhenInactive : 1;
   bool mIsPrerendered : 1;
   bool mIsAppTab : 1;
   bool mUseGlobalHistory : 1;
   bool mUseRemoteTabs : 1;
+  bool mUseTrackingProtection : 1;
   bool mDeviceSizeIsPageSize : 1;
   bool mWindowDraggingAllowed : 1;
   bool mInFrameSwap : 1;
   bool mInheritPrivateBrowsingId : 1;
 
   // Because scriptability depends on the mAllowJavascript values of our
   // ancestors, we cache the effective scriptability and recompute it when
   // it might have changed;

--- a/docshell/base/nsIDocShell.idl
+++ b/docshell/base/nsIDocShell.idl
@@ -1126,9 +1126,14 @@ interface nsIDocShell : nsIDocShellTreeI
    */
   [infallible] readonly attribute boolean isOnlyToplevelInTabGroup;
 
   /**
    * Returns `true` if this docshell was created due to a Large-Allocation
    * header, and has not seen the initiating load yet.
    */
   [infallible] readonly attribute boolean awaitingLargeAlloc;
+
+  /**
+   * Attribute that determines whether tracking protection is enabled.
+   */
+  attribute boolean useTrackingProtection;
 };

--- a/docshell/base/nsILoadContext.idl
+++ b/docshell/base/nsILoadContext.idl
@@ -73,31 +73,46 @@ interface nsILoadContext : nsISupports
    */
   attribute boolean usePrivateBrowsing;
 
   /**
    * Attribute that determines if remote (out-of-process) tabs should be used.
    */
   readonly attribute boolean useRemoteTabs;
 
+  /*
+   * Attribute that determines if tracking protection should be used. May not be
+   * changed after a document has been loaded in this context.
+   */
+  attribute boolean useTrackingProtection;
+
 %{C++
   /**
    * De-XPCOMed getter to make call-sites cleaner.
    */
-  bool UsePrivateBrowsing() {
-    bool usingPB;
+  bool UsePrivateBrowsing()
+  {
+    bool usingPB = false;
     GetUsePrivateBrowsing(&usingPB);
     return usingPB;
   }
 
-  bool UseRemoteTabs() {
-    bool usingRT;
+  bool UseRemoteTabs()
+  {
+    bool usingRT = false;
     GetUseRemoteTabs(&usingRT);
     return usingRT;
   }
+
+  bool UseTrackingProtection()
+  {
+    bool usingTP = false;
+    GetUseTrackingProtection(&usingTP);
+    return usingTP;
+  }
 %}
 
   /**
    * Set the private browsing state of the load context, meant to be used internally.
    */
   [noscript] void SetPrivateBrowsing(in boolean aInPrivateBrowsing);
 
   /**
@@ -125,25 +140,9 @@ interface nsILoadContext : nsISupports
   /**
    * The C++ getter for origin attributes.
    *
    * Defined in LoadContext.cpp
    */
   bool GetOriginAttributes(mozilla::OriginAttributes& aAttrs);
 #endif
 %}
-
-  /**
-   * Returns true if tracking protection is enabled for the load context.
-   */
-  boolean IsTrackingProtectionOn();
-
-%{C++
-  /**
-   * De-XPCOMed getter to make call-sites cleaner.
-   */
-  bool UseTrackingProtection() {
-    bool usingTP;
-    IsTrackingProtectionOn(&usingTP);
-    return usingTP;
-  }
-%}
 };

--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -3439,22 +3439,22 @@ nsContentUtils::IsDraggableImage(nsICont
 bool
 nsContentUtils::IsDraggableLink(const nsIContent* aContent) {
   nsCOMPtr<nsIURI> absURI;
   return aContent->IsLink(getter_AddRefs(absURI));
 }
 
 // static
 nsresult
-nsContentUtils::NameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsIAtom* aName,
-                            mozilla::dom::NodeInfo** aResult)
+nsContentUtils::QNameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsIAtom* aName,
+                             mozilla::dom::NodeInfo** aResult)
 {
   nsNodeInfoManager *niMgr = aNodeInfo->NodeInfoManager();
 
-  *aResult = niMgr->GetNodeInfo(aName, aNodeInfo->GetPrefixAtom(),
+  *aResult = niMgr->GetNodeInfo(aName, nullptr,
                                 aNodeInfo->NamespaceID(),
                                 aNodeInfo->NodeType(),
                                 aNodeInfo->GetExtraName()).take();
   return NS_OK;
 }
 
 
 static bool

--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -791,21 +791,23 @@ public:
    * Method that decides whether a content node is a draggable link
    *
    * @param aContent The content node to test.
    * @return whether it's a draggable link
    */
   static bool IsDraggableLink(const nsIContent* aContent);
 
   /**
-   * Convenience method to create a new nodeinfo that differs only by name
-   * from aNodeInfo.
+   * Convenience method to create a new nodeinfo that differs only by prefix and
+   * name from aNodeInfo. The new nodeinfo's name is set to aName, and prefix is
+   * set to null.
    */
-  static nsresult NameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsIAtom* aName,
-                              mozilla::dom::NodeInfo** aResult);
+  static nsresult QNameChanged(mozilla::dom::NodeInfo* aNodeInfo,
+                               nsIAtom* aName,
+                               mozilla::dom::NodeInfo** aResult);
 
   /**
    * Returns the appropriate event argument names for the specified
    * namespace and event name.  Added because we need to switch between
    * SVG's "evt" and the rest of the world's "event", and because onerror
    * on window takes 5 args.
    */
   static void GetEventArgNames(int32_t aNameSpaceID, nsIAtom *aEventName,

--- a/dom/base/nsCopySupport.cpp
+++ b/dom/base/nsCopySupport.cpp
@@ -750,18 +750,23 @@ nsCopySupport::FireClipboardEvent(EventM
                                   nsIPresShell* aPresShell,
                                   nsISelection* aSelection,
                                   bool* aActionTaken)
 {
   if (aActionTaken) {
     *aActionTaken = false;
   }
 
-  NS_ASSERTION(aEventMessage == eCut || aEventMessage == eCopy ||
-               aEventMessage == ePaste,
+  EventMessage originalEventMessage = aEventMessage;
+  if (originalEventMessage == ePasteNoFormatting) {
+    originalEventMessage = ePaste;
+  }
+
+  NS_ASSERTION(originalEventMessage == eCut || originalEventMessage == eCopy ||
+               originalEventMessage == ePaste,
                "Invalid clipboard event type");
 
   nsCOMPtr<nsIPresShell> presShell = aPresShell;
   if (!presShell)
     return false;
 
   nsCOMPtr<nsIDocument> doc = presShell->GetDocument();
   if (!doc)
@@ -808,31 +813,31 @@ nsCopySupport::FireClipboardEvent(EventM
     docShell && docShell->ItemType() == nsIDocShellTreeItem::typeChrome;
 
   // next, fire the cut, copy or paste event
   bool doDefault = true;
   RefPtr<DataTransfer> clipboardData;
   if (chromeShell || Preferences::GetBool("dom.event.clipboardevents.enabled", true)) {
     clipboardData =
       new DataTransfer(doc->GetScopeObject(), aEventMessage,
-                       aEventMessage == ePaste, aClipboardType);
+                       originalEventMessage == ePaste, aClipboardType);
 
     nsEventStatus status = nsEventStatus_eIgnore;
-    InternalClipboardEvent evt(true, aEventMessage);
+    InternalClipboardEvent evt(true, originalEventMessage);
     evt.mClipboardData = clipboardData;
     EventDispatcher::Dispatch(content, presShell->GetPresContext(), &evt,
                               nullptr, &status);
     // If the event was cancelled, don't do the clipboard operation
     doDefault = (status != nsEventStatus_eConsumeNoDefault);
   }
 
   // No need to do anything special during a paste. Either an event listener
   // took care of it and cancelled the event, or the caller will handle it.
   // Return true to indicate that the event wasn't cancelled.
-  if (aEventMessage == ePaste) {
+  if (originalEventMessage == ePaste) {
     // Clear and mark the clipboardData as readonly. This prevents someone
     // from reading the clipboard contents after the paste event has fired.
     if (clipboardData) {
       clipboardData->ClearAll();
       clipboardData->SetReadOnly();
     }
 
     if (aActionTaken) {
@@ -862,17 +867,17 @@ nsCopySupport::FireClipboardEvent(EventM
     if (formControl) {
       if (formControl->GetType() == NS_FORM_INPUT_PASSWORD) {
         return false;
       }
     }
 
     // when cutting non-editable content, do nothing
     // XXX this is probably the wrong editable flag to check
-    if (aEventMessage != eCut || content->IsEditable()) {
+    if (originalEventMessage != eCut || content->IsEditable()) {
       // get the data from the selection if any
       bool isCollapsed;
       sel->GetIsCollapsed(&isCollapsed);
       if (isCollapsed) {
         if (aActionTaken) {
           *aActionTaken = true;
         }
         return false;

--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -1645,19 +1645,19 @@ nsDOMWindowUtils::DisableNonTestMouseEve
 
 NS_IMETHODIMP
 nsDOMWindowUtils::SuppressEventHandling(bool aSuppress)
 {
   nsCOMPtr<nsIDocument> doc = GetDocument();
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
 
   if (aSuppress) {
-    doc->SuppressEventHandling(nsIDocument::eEvents);
+    doc->SuppressEventHandling();
   } else {
-    doc->UnsuppressEventHandlingAndFireEvents(nsIDocument::eEvents, true);
+    doc->UnsuppressEventHandlingAndFireEvents(true);
   }
 
   return NS_OK;
 }
 
 static nsresult
 getScrollXYAppUnits(const nsWeakPtr& aWindow, bool aFlushLayout, nsPoint& aScrollPos) {
   nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(aWindow);

--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -1353,17 +1353,16 @@ nsIDocument::nsIDocument()
 #endif
     mBidiOptions(IBMBIDI_DEFAULT_BIDI_OPTIONS),
     mSandboxFlags(0),
     mPartID(0),
     mMarkedCCGeneration(0),
     mPresShell(nullptr),
     mSubtreeModifiedDepth(0),
     mEventsSuppressed(0),
-    mAnimationsPaused(0),
     mExternalScriptsBeingEvaluated(0),
     mFrameRequestCallbackCounter(0),
     mStaticCloneCount(0),
     mWindow(nullptr),
     mBFCacheEntry(nullptr),
     mInSyncOperationCount(0),
     mBlockDOMContentLoaded(0),
     mDidFireDOMContentLoaded(true),
@@ -3806,17 +3805,17 @@ nsDocument::CreateShell(nsPresContext* a
   RebuildUserFontSet();
 
   return shell.forget();
 }
 
 void
 nsDocument::MaybeRescheduleAnimationFrameNotifications()
 {
-  if (!mPresShell || !IsEventHandlingEnabled() || AnimationsPaused()) {
+  if (!mPresShell || !IsEventHandlingEnabled()) {
     // bail out for now, until one of those conditions changes
     return;
   }
 
   nsRefreshDriver* rd = mPresShell->GetPresContext()->RefreshDriver();
   if (!mFrameRequestCallbacks.IsEmpty()) {
     rd->ScheduleFrameRequestCallbacks(this);
   }
@@ -3869,17 +3868,17 @@ nsIDocument::ShouldThrottleFrameRequests
   // We got painted during the last paint, so run at full speed.
   return false;
 }
 
 void
 nsDocument::DeleteShell()
 {
   mExternalResourceMap.HideViewers();
-  if (IsEventHandlingEnabled() && !AnimationsPaused()) {
+  if (IsEventHandlingEnabled()) {
     RevokeAnimationFrameNotifications();
   }
   if (nsPresContext* presContext = mPresShell->GetPresContext()) {
     presContext->RefreshDriver()->CancelPendingEvents(this);
   }
 
   // When our shell goes away, request that all our images be immediately
   // discarded, so we don't carry around decoded image data for a document we
@@ -4651,17 +4650,17 @@ nsDocument::SetScriptGlobalObject(nsIScr
                nsSMILTimeContainer::PAUSE_BEGIN),
              "Clearing window pointer while animations are unpaused");
 
   if (mScriptGlobalObject && !aScriptGlobalObject) {
     // We're detaching from the window.  We need to grab a pointer to
     // our layout history state now.
     mLayoutHistoryState = GetLayoutHistoryState();
 
-    if (mPresShell && !EventHandlingSuppressed() && !AnimationsPaused()) {
+    if (mPresShell && !EventHandlingSuppressed()) {
       RevokeAnimationFrameNotifications();
     }
 
     // Also make sure to remove our onload blocker now if we haven't done it yet
     if (mOnloadBlockCount != 0) {
       nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
       if (loadGroup) {
         loadGroup->RemoveRequest(mOnloadBlocker, nullptr, NS_OK);
@@ -9320,54 +9319,38 @@ nsIDocument::GetReadyState(nsAString& aR
   case READYSTATE_COMPLETE :
     aReadyState.AssignLiteral(u"complete");
     break;
   default:
     aReadyState.AssignLiteral(u"uninitialized");
   }
 }
 
-namespace {
-
-struct SuppressArgs
-{
-  nsIDocument::SuppressionType mWhat;
-  uint32_t mIncrease;
-};
-
-} // namespace
-
 static bool
 SuppressEventHandlingInDocument(nsIDocument* aDocument, void* aData)
 {
-  SuppressArgs* args = static_cast<SuppressArgs*>(aData);
-  aDocument->SuppressEventHandling(args->mWhat, args->mIncrease);
+  aDocument->SuppressEventHandling(*static_cast<uint32_t*>(aData));
+
   return true;
 }
 
 void
-nsDocument::SuppressEventHandling(nsIDocument::SuppressionType aWhat,
-                                  uint32_t aIncrease)
-{
-  if (mEventsSuppressed == 0 && mAnimationsPaused == 0 &&
-      aIncrease != 0 && mPresShell && mScriptGlobalObject) {
+nsDocument::SuppressEventHandling(uint32_t aIncrease)
+{
+  if (mEventsSuppressed == 0 && aIncrease != 0 && mPresShell &&
+      mScriptGlobalObject) {
     RevokeAnimationFrameNotifications();
   }
 
-  if (aWhat == eAnimationsOnly) {
-    mAnimationsPaused += aIncrease;
-  } else {
-    mEventsSuppressed += aIncrease;
-    for (uint32_t i = 0; i < aIncrease; ++i) {
-      ScriptLoader()->AddExecuteBlocker();
-    }
-  }
-
-  SuppressArgs args = { aWhat, aIncrease };
-  EnumerateSubDocuments(SuppressEventHandlingInDocument, &args);
+  mEventsSuppressed += aIncrease;
+  for (uint32_t i = 0; i < aIncrease; ++i) {
+    ScriptLoader()->AddExecuteBlocker();
+  }
+
+  EnumerateSubDocuments(SuppressEventHandlingInDocument, &aIncrease);
 }
 
 static void
 FireOrClearDelayedEvents(nsTArray<nsCOMPtr<nsIDocument> >& aDocuments,
                          bool aFireEvents)
 {
   nsIFocusManager* fm = nsFocusManager::GetFocusManager();
   if (!fm)
@@ -9659,72 +9642,45 @@ public:
     FireOrClearDelayedEvents(mDocuments, true);
     return NS_OK;
   }
 
 private:
   nsTArray<nsCOMPtr<nsIDocument> > mDocuments;
 };
 
-namespace {
-
-struct UnsuppressArgs
-{
-  explicit UnsuppressArgs(nsIDocument::SuppressionType aWhat)
-    : mWhat(aWhat)
-  {
-  }
-
-  nsIDocument::SuppressionType mWhat;
-  nsTArray<nsCOMPtr<nsIDocument>> mDocs;
-};
-
-} // namespace
-
 static bool
 GetAndUnsuppressSubDocuments(nsIDocument* aDocument,
                              void* aData)
 {
-  UnsuppressArgs* args = static_cast<UnsuppressArgs*>(aData);
-  if (args->mWhat != nsIDocument::eAnimationsOnly &&
-      aDocument->EventHandlingSuppressed() > 0) {
+  if (aDocument->EventHandlingSuppressed() > 0) {
     static_cast<nsDocument*>(aDocument)->DecreaseEventSuppression();
     aDocument->ScriptLoader()->RemoveExecuteBlocker();
-  } else if (args->mWhat == nsIDocument::eAnimationsOnly &&
-             aDocument->AnimationsPaused()) {
-    static_cast<nsDocument*>(aDocument)->ResumeAnimations();
-  }
-
-  if (args->mWhat != nsIDocument::eAnimationsOnly) {
-    // No need to remember documents if we only care about animation frames.
-    args->mDocs.AppendElement(aDocument);
-  }
-
+  }
+
+  nsTArray<nsCOMPtr<nsIDocument> >* docs =
+    static_cast<nsTArray<nsCOMPtr<nsIDocument> >* >(aData);
+
+  docs->AppendElement(aDocument);
   aDocument->EnumerateSubDocuments(GetAndUnsuppressSubDocuments, aData);
   return true;
 }
 
 void
-nsDocument::UnsuppressEventHandlingAndFireEvents(nsIDocument::SuppressionType aWhat,
-                                                 bool aFireEvents)
-{
-  UnsuppressArgs args(aWhat);
-  GetAndUnsuppressSubDocuments(this, &args);
-
-  if (aWhat == nsIDocument::eAnimationsOnly) {
-    // No need to fire events if we only care about animations here.
-    return;
-  }
+nsDocument::UnsuppressEventHandlingAndFireEvents(bool aFireEvents)
+{
+  nsTArray<nsCOMPtr<nsIDocument>> documents;
+  GetAndUnsuppressSubDocuments(this, &documents);
 
   if (aFireEvents) {
     MOZ_RELEASE_ASSERT(NS_IsMainThread());
-    nsCOMPtr<nsIRunnable> ded = new nsDelayedEventDispatcher(args.mDocs);
+    nsCOMPtr<nsIRunnable> ded = new nsDelayedEventDispatcher(documents);
     Dispatch("nsDelayedEventDispatcher", TaskCategory::Other, ded.forget());
   } else {
-    FireOrClearDelayedEvents(args.mDocs, false);
+    FireOrClearDelayedEvents(documents, false);
   }
 }
 
 nsISupports*
 nsDocument::GetCurrentContentSink()
 {
   return mParser ? mParser->GetContentSink() : nullptr;
 }
@@ -10039,33 +9995,32 @@ nsIDocument::ScheduleFrameRequestCallbac
     return NS_ERROR_NOT_AVAILABLE;
   }
   int32_t newHandle = ++mFrameRequestCallbackCounter;
 
   bool alreadyRegistered = !mFrameRequestCallbacks.IsEmpty();
   DebugOnly<FrameRequest*> request =
     mFrameRequestCallbacks.AppendElement(FrameRequest(aCallback, newHandle));
   NS_ASSERTION(request, "This is supposed to be infallible!");
-  if (!alreadyRegistered && mPresShell && IsEventHandlingEnabled() &&
-      !AnimationsPaused()) {
+  if (!alreadyRegistered && mPresShell && IsEventHandlingEnabled()) {
     mPresShell->GetPresContext()->RefreshDriver()->
       ScheduleFrameRequestCallbacks(this);
   }
 
   *aHandle = newHandle;
   return NS_OK;
 }
 
 void
 nsIDocument::CancelFrameRequestCallback(int32_t aHandle)
 {
   // mFrameRequestCallbacks is stored sorted by handle
   if (mFrameRequestCallbacks.RemoveElementSorted(aHandle) &&
       mFrameRequestCallbacks.IsEmpty() &&
-      mPresShell && IsEventHandlingEnabled() && !AnimationsPaused()) {
+      mPresShell && IsEventHandlingEnabled()) {
     mPresShell->GetPresContext()->RefreshDriver()->
       RevokeFrameRequestCallbacks(this);
   }
 }
 
 nsresult
 nsDocument::GetStateObject(nsIVariant** aState)
 {

--- a/dom/base/nsDocument.h
+++ b/dom/base/nsDocument.h
@@ -902,34 +902,26 @@ public:
   GetPendingAnimationTracker() final override
   {
     return mPendingAnimationTracker;
   }
 
   virtual mozilla::PendingAnimationTracker*
   GetOrCreatePendingAnimationTracker() override;
 
-  virtual void SuppressEventHandling(SuppressionType aWhat,
-                                     uint32_t aIncrease) override;
+  virtual void SuppressEventHandling(uint32_t aIncrease) override;
 
-  virtual void UnsuppressEventHandlingAndFireEvents(SuppressionType aWhat,
-                                                    bool aFireEvents) override;
+  virtual void UnsuppressEventHandlingAndFireEvents(bool aFireEvents) override;
 
   void DecreaseEventSuppression() {
     MOZ_ASSERT(mEventsSuppressed);
     --mEventsSuppressed;
     MaybeRescheduleAnimationFrameNotifications();
   }
 
-  void ResumeAnimations() {
-    MOZ_ASSERT(mAnimationsPaused);
-    --mAnimationsPaused;
-    MaybeRescheduleAnimationFrameNotifications();
-  }
-
   virtual nsIDocument* GetTemplateContentsOwner() override;
 
   NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_AMBIGUOUS(nsDocument,
                                                                    nsIDocument)
 
   void DoNotifyPossibleTitleChange();
 
   nsExternalResourceMap& ExternalResourceMap()

--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -1999,21 +1999,18 @@ nsGlobalWindow::FreeInnerObjects()
 
   if (mDoc) {
     // Remember the document's principal and URI.
     mDocumentPrincipal = mDoc->NodePrincipal();
     mDocumentURI = mDoc->GetDocumentURI();
     mDocBaseURI = mDoc->GetDocBaseURI();
 
     while (mDoc->EventHandlingSuppressed()) {
-      mDoc->UnsuppressEventHandlingAndFireEvents(nsIDocument::eEvents, false);
-    }
-
-    // Note: we don't have to worry about eAnimationsOnly suppressions because
-    // they won't leak.
+      mDoc->UnsuppressEventHandlingAndFireEvents(false);
+    }
   }
 
   // Remove our reference to the document and the document principal.
   mFocusedNode = nullptr;
 
   if (mApplicationCache) {
     static_cast<nsDOMOfflineResourceList*>(mApplicationCache.get())->Disconnect();
     mApplicationCache = nullptr;
@@ -9261,17 +9258,17 @@ nsGlobalWindow::EnterModalState()
     nsIPresShell::SetCapturingContent(nullptr, 0);
   }
 
   if (topWin->mModalStateDepth == 0) {
     NS_ASSERTION(!topWin->mSuspendedDoc, "Shouldn't have mSuspendedDoc here!");
 
     topWin->mSuspendedDoc = topDoc;
     if (topDoc) {
-      topDoc->SuppressEventHandling(nsIDocument::eEvents);
+      topDoc->SuppressEventHandling();
     }
 
     nsGlobalWindow* inner = topWin->GetCurrentInnerWindowInternal();
     if (inner) {
       topWin->GetCurrentInnerWindowInternal()->Suspend();
     }
   }
   topWin->mModalStateDepth++;
@@ -9298,18 +9295,17 @@ nsGlobalWindow::LeaveModalState()
 
   if (topWin->mModalStateDepth == 0) {
     if (inner) {
       inner->Resume();
     }
 
     if (topWin->mSuspendedDoc) {
       nsCOMPtr<nsIDocument> currentDoc = topWin->GetExtantDoc();
-      topWin->mSuspendedDoc->UnsuppressEventHandlingAndFireEvents(nsIDocument::eEvents,
-                                                                  currentDoc == topWin->mSuspendedDoc);
+      topWin->mSuspendedDoc->UnsuppressEventHandlingAndFireEvents(currentDoc == topWin->mSuspendedDoc);
       topWin->mSuspendedDoc = nullptr;
     }
   }
 
   // Remember the time of the last dialog quit.
   if (inner) {
     inner->mLastDialogQuitTime = TimeStamp::Now();
   }

--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -2153,41 +2153,30 @@ public:
   virtual mozilla::PendingAnimationTracker* GetPendingAnimationTracker() = 0;
 
   // Gets the tracker for animations that are waiting to start and
   // creates it if it doesn't already exist. As a result, the return value
   // will never be nullptr.
   virtual mozilla::PendingAnimationTracker*
   GetOrCreatePendingAnimationTracker() = 0;
 
-  enum SuppressionType {
-    eAnimationsOnly = 0x1,
-
-    // Note that suppressing events also suppresses animation frames, so
-    // there's no need to split out events in its own bitmask.
-    eEvents = 0x3,
-  };
-
   /**
    * Prevents user initiated events from being dispatched to the document and
    * subdocuments.
    */
-  virtual void SuppressEventHandling(SuppressionType aWhat,
-                                     uint32_t aIncrease = 1) = 0;
+  virtual void SuppressEventHandling(uint32_t aIncrease = 1) = 0;
 
   /**
    * Unsuppress event handling.
    * @param aFireEvents If true, delayed events (focus/blur) will be fired
    *                    asynchronously.
    */
-  virtual void UnsuppressEventHandlingAndFireEvents(SuppressionType aWhat,
-                                                    bool aFireEvents) = 0;
+  virtual void UnsuppressEventHandlingAndFireEvents(bool aFireEvents) = 0;
 
   uint32_t EventHandlingSuppressed() const { return mEventsSuppressed; }
-  uint32_t AnimationsPaused() const { return mAnimationsPaused; }
 
   bool IsEventHandlingEnabled() {
     return !EventHandlingSuppressed() && mScriptGlobalObject;
   }
 
   /**
    * Increment the number of external scripts being evaluated.
    */
@@ -3277,18 +3266,16 @@ protected:
 
   // If we're an external resource document, this will be non-null and will
   // point to our "display document": the one that all resource lookups should
   // go to.
   nsCOMPtr<nsIDocument> mDisplayDocument;
 
   uint32_t mEventsSuppressed;
 
-  uint32_t mAnimationsPaused;
-
   /**
    * The number number of external scripts (ones with the src attribute) that
    * have this document as their owner and that are being evaluated right now.
    */
   uint32_t mExternalScriptsBeingEvaluated;
 
   /**
    * The current frame request callback handle

--- a/dom/bindings/BindingUtils.cpp
+++ b/dom/bindings/BindingUtils.cpp
@@ -2782,17 +2782,17 @@ void
 HandlePrerenderingViolation(nsPIDOMWindowInner* aWindow)
 {
   // Freeze the window and its workers, and its children too.
   aWindow->Freeze();
 
   // Suspend event handling on the document
   nsCOMPtr<nsIDocument> doc = aWindow->GetExtantDoc();
   if (doc) {
-    doc->SuppressEventHandling(nsIDocument::eEvents);
+    doc->SuppressEventHandling();
   }
 }
 
 bool
 EnforceNotInPrerendering(JSContext* aCx, JSObject* aObj)
 {
   JS::Rooted<JSObject*> thisObj(aCx, js::CheckedUnwrap(aObj));
   if (!thisObj) {

--- a/dom/events/DataTransfer.cpp
+++ b/dom/events/DataTransfer.cpp
@@ -100,18 +100,21 @@ DataTransfer::DataTransfer(nsISupports* 
   // For these events, we want to be able to add data to the data transfer, so
   // clear the readonly state. Otherwise, the data is already present. For
   // external usage, cache the data from the native clipboard or drag.
   if (aEventMessage == eCut ||
       aEventMessage == eCopy ||
       aEventMessage == eDragStart) {
     mReadOnly = false;
   } else if (mIsExternal) {
-    if (aEventMessage == ePaste) {
-      CacheExternalClipboardFormats();
+    if (aEventMessage == ePasteNoFormatting) {
+      mEventMessage = ePaste;
+      CacheExternalClipboardFormats(true);
+    } else if (aEventMessage == ePaste) {
+      CacheExternalClipboardFormats(false);
     } else if (aEventMessage >= eDragDropEventFirst &&
                aEventMessage <= eDragDropEventLast) {
       CacheExternalDragFormats();
     }
   }
 }
 
 DataTransfer::DataTransfer(nsISupports* aParent,
@@ -1351,17 +1354,17 @@ DataTransfer::CacheExternalDragFormats()
       if (supported) {
         CacheExternalData(formats[f], c, sysPrincipal, /* hidden = */ f && hasFileData);
       }
     }
   }
 }
 
 void
-DataTransfer::CacheExternalClipboardFormats()
+DataTransfer::CacheExternalClipboardFormats(bool aPlainTextOnly)
 {
   NS_ASSERTION(mEventMessage == ePaste,
                "caching clipboard data for invalid event");
 
   // Called during the constructor for paste events to cache the formats
   // available on the clipboard. As with CacheExternalDragFormats, the
   // data will only be retrieved when needed.
 
@@ -1370,16 +1373,27 @@ DataTransfer::CacheExternalClipboardForm
   if (!clipboard || mClipboardType < 0) {
     return;
   }
 
   nsIScriptSecurityManager* ssm = nsContentUtils::GetSecurityManager();
   nsCOMPtr<nsIPrincipal> sysPrincipal;
   ssm->GetSystemPrincipal(getter_AddRefs(sysPrincipal));
 
+  if (aPlainTextOnly) {
+    bool supported;
+    const char* unicodeMime[] = { kUnicodeMime };
+    clipboard->HasDataMatchingFlavors(unicodeMime, 1, mClipboardType,
+                                      &supported);
+    if (supported) {
+      CacheExternalData(kUnicodeMime, 0, sysPrincipal, false);
+    }
+    return;
+  }
+
   // Check if the clipboard has any files
   bool hasFileData = false;
   const char *fileMime[] = { kFileMime };
   clipboard->HasDataMatchingFlavors(fileMime, 1, mClipboardType, &hasFileData);
 
   // We will be ignoring any application/x-moz-file files found in the paste
   // datatransfer within e10s, as they will fail to be sent over IPC. Because of
   // that, we will unset hasFileData, whether or not it would have been set.

--- a/dom/events/DataTransfer.h
+++ b/dom/events/DataTransfer.h
@@ -302,17 +302,17 @@ protected:
   nsresult CacheExternalData(const char* aFormat, uint32_t aIndex,
                              nsIPrincipal* aPrincipal, bool aHidden);
 
   // caches the formats that exist in the drag service that were added by an
   // external drag
   void CacheExternalDragFormats();
 
   // caches the formats that exist in the clipboard
-  void CacheExternalClipboardFormats();
+  void CacheExternalClipboardFormats(bool aPlainTextOnly);
 
   FileList* GetFilesInternal(ErrorResult& aRv, nsIPrincipal* aSubjectPrincipal);
   nsresult GetDataAtInternal(const nsAString& aFormat, uint32_t aIndex,
                              nsIPrincipal* aSubjectPrincipal,
                              nsIVariant** aData);
 
   nsresult SetDataAtInternal(const nsAString& aFormat, nsIVariant* aData,
                              uint32_t aIndex, nsIPrincipal* aSubjectPrincipal);

--- a/dom/events/test/mochitest.ini
+++ b/dom/events/test/mochitest.ini
@@ -134,16 +134,18 @@ support-files = bug1017086_inner.html
 [test_bug1017086_enable.html]
 support-files = bug1017086_inner.html
 [test_bug1079236.html]
 [test_bug1145910.html]
 [test_bug1150308.html]
 [test_bug1248459.html]
 [test_bug1264380.html]
 run-if = (e10s && os != "win") # Bug 1270043, crash at windows platforms; Bug1264380 comment 20, nsDragService::InvokeDragSessionImpl behaves differently among platform implementations in non-e10s mode which prevents us to check the validity of nsIDragService::getCurrentSession() consistently via synthesize mouse clicks in non-e10s mode.
+[test_bug1327798.html]
+subsuite = clipboard
 [test_clickevent_on_input.html]
 skip-if = toolkit == 'android' #CRASH_DUMP, RANDOM
 [test_continuous_wheel_events.html]
 [test_dblclick_explicit_original_target.html]
 [test_dom_activate_event.html]
 [test_dom_keyboard_event.html]
 skip-if = toolkit == 'android' #CRASH_DUMP, RANDOM
 [test_dom_mouse_event.html]

new file mode 100644
--- /dev/null
+++ b/dom/events/test/test_bug1327798.html
@@ -0,0 +1,47 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test for bug 1327798</title>
+<script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+<script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+<link rel="stylesheet" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?=id=1327798">Mozilla Bug 1327798</a>
+<p id="display"></p>
+<div id="content" style="display: none;"></div>
+
+<div contenteditable="true" id="editable1"><b>Formatted Text</b><br></div>
+<pre>
+<script class="testbody" type="application/javascript">
+SimpleTest.waitForExplicitFinish();
+SimpleTest.waitForFocus(() => {
+  var editable = document.getElementById("editable1");
+  editable.focus();
+
+  window.getSelection().selectAllChildren(editable1);
+
+  SpecialPowers.doCommand(window, "cmd_copy");
+
+  //--------- now check the content of the clipboard
+  var clipboard = SpecialPowers.Cc["@mozilla.org/widget/clipboard;1"]
+                               .getService(SpecialPowers.Ci.nsIClipboard);
+  // does the clipboard contain text/unicode data ?
+  ok(clipboard.hasDataMatchingFlavors(["text/unicode"], 1, clipboard.kGlobalClipboard),
+     "clipboard contains unicode text");
+  // does the clipboard contain text/html data ?
+  ok(clipboard.hasDataMatchingFlavors(["text/html"], 1, clipboard.kGlobalClipboard),
+     "clipboard contains html text");
+
+  window.addEventListener("paste", (e) => {
+    ok(e.clipboardData.types.indexOf('text/html'), -1, "clipboardData shouldn't have text/html");
+    ok(e.clipboardData.getData('text/plain'), "Formatted Text",  "getData(text/plain) should return plain text");
+    SimpleTest.finish();
+  });
+
+  SpecialPowers.doCommand(window, "cmd_pasteNoFormatting");
+});
+</script>
+</pre>
+</body>
+</html>

--- a/dom/html/HTMLSelectElement.cpp
+++ b/dom/html/HTMLSelectElement.cpp
@@ -712,18 +712,18 @@ HTMLSelectElement::SetLength(uint32_t aL
   } else if (aLength > curlen) {
     if (aLength > MAX_DYNAMIC_SELECT_LENGTH) {
       aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
       return;
     }
 
     RefPtr<mozilla::dom::NodeInfo> nodeInfo;
 
-    nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::option,
-                                getter_AddRefs(nodeInfo));
+    nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::option,
+                                 getter_AddRefs(nodeInfo));
 
     nsCOMPtr<nsINode> node = NS_NewHTMLOptionElement(nodeInfo.forget());
 
     RefPtr<nsTextNode> text = new nsTextNode(mNodeInfo->NodeInfoManager());
 
     aRv = node->AppendChildTo(text, false);
     if (aRv.Failed()) {
       return;

--- a/dom/html/HTMLTableElement.cpp
+++ b/dom/html/HTMLTableElement.cpp
@@ -398,26 +398,37 @@ HTMLTableElement::TBodies()
 
 already_AddRefed<nsGenericHTMLElement>
 HTMLTableElement::CreateTHead()
 {
   RefPtr<nsGenericHTMLElement> head = GetTHead();
   if (!head) {
     // Create a new head rowgroup.
     RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-    nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::thead,
-                                getter_AddRefs(nodeInfo));
+    nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::thead,
+                                 getter_AddRefs(nodeInfo));
 
     head = NS_NewHTMLTableSectionElement(nodeInfo.forget());
     if (!head) {
       return nullptr;
     }
 
-    ErrorResult rv;
-    nsCOMPtr<nsINode> refNode = nsINode::GetFirstChild();
+    nsCOMPtr<nsIContent> refNode = nullptr;
+    for (refNode = nsINode::GetFirstChild();
+         refNode;
+         refNode = refNode->GetNextSibling()) {
+
+      if (refNode->IsHTMLElement() &&
+          !refNode->IsHTMLElement(nsGkAtoms::caption) &&
+          !refNode->IsHTMLElement(nsGkAtoms::colgroup)) {
+        break;
+      }
+    }
+
+    IgnoredErrorResult rv;
     nsINode::InsertBefore(*head, refNode, rv);
   }
   return head.forget();
 }
 
 void
 HTMLTableElement::DeleteTHead()
 {
@@ -431,18 +442,18 @@ HTMLTableElement::DeleteTHead()
 
 already_AddRefed<nsGenericHTMLElement>
 HTMLTableElement::CreateTFoot()
 {
   RefPtr<nsGenericHTMLElement> foot = GetTFoot();
   if (!foot) {
     // create a new foot rowgroup
     RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-    nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::tfoot,
-                                getter_AddRefs(nodeInfo));
+    nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::tfoot,
+                                 getter_AddRefs(nodeInfo));
 
     foot = NS_NewHTMLTableSectionElement(nodeInfo.forget());
     if (!foot) {
       return nullptr;
     }
     AppendChildTo(foot, true);
   }
 
@@ -462,25 +473,27 @@ HTMLTableElement::DeleteTFoot()
 
 already_AddRefed<nsGenericHTMLElement>
 HTMLTableElement::CreateCaption()
 {
   RefPtr<nsGenericHTMLElement> caption = GetCaption();
   if (!caption) {
     // Create a new caption.
     RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-    nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::caption,
-                                getter_AddRefs(nodeInfo));
+    nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::caption,
+                                 getter_AddRefs(nodeInfo));
 
     caption = NS_NewHTMLTableCaptionElement(nodeInfo.forget());
     if (!caption) {
       return nullptr;
     }
 
-    AppendChildTo(caption, true);
+    IgnoredErrorResult rv;
+    nsCOMPtr<nsINode> firsChild = nsINode::GetFirstChild();
+    nsINode::InsertBefore(*caption, firsChild, rv);
   }
   return caption.forget();
 }
 
 void
 HTMLTableElement::DeleteCaption()
 {
   HTMLTableCaptionElement* caption = GetCaption();
@@ -509,17 +522,17 @@ HTMLTableElement::CreateTBody()
        child;
        child = child->GetPreviousSibling()) {
     if (child->IsHTMLElement(nsGkAtoms::tbody)) {
       referenceNode = child->GetNextSibling();
       break;
     }
   }
 
-  ErrorResult rv;
+  IgnoredErrorResult rv;
   nsINode::InsertBefore(*newBody, referenceNode, rv);
 
   return newBody.forget();
 }
 
 already_AddRefed<nsGenericHTMLElement>
 HTMLTableElement::InsertRow(int32_t aIndex, ErrorResult& aError)
 {
@@ -555,18 +568,18 @@ HTMLTableElement::InsertRow(int32_t aInd
       refIndex = rowCount - 1;
     }
 
     RefPtr<Element> refRow = rows->Item(refIndex);
     nsCOMPtr<nsINode> parent = refRow->GetParentNode();
 
     // create the row
     RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-    nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::tr,
-                                getter_AddRefs(nodeInfo));
+    nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::tr,
+                                 getter_AddRefs(nodeInfo));
 
     newRow = NS_NewHTMLTableRowElement(nodeInfo.forget());
 
     if (newRow) {
       // If aIndex is -1 or equal to the number of rows, the new row
       // is appended.
       if (aIndex == -1 || uint32_t(aIndex) == rowCount) {
         parent->AppendChild(*newRow, aError);
@@ -589,32 +602,32 @@ HTMLTableElement::InsertRow(int32_t aInd
       if (child->IsHTMLElement(nsGkAtoms::tbody)) {
         rowGroup = child;
         break;
       }
     }
 
     if (!rowGroup) { // need to create a TBODY
       RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-      nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::tbody,
-                                  getter_AddRefs(nodeInfo));
+      nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::tbody,
+                                   getter_AddRefs(nodeInfo));
 
       rowGroup = NS_NewHTMLTableSectionElement(nodeInfo.forget());
       if (rowGroup) {
         aError = AppendChildTo(rowGroup, true);
         if (aError.Failed()) {
           return nullptr;
         }
       }
     }
 
     if (rowGroup) {
       RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-      nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::tr,
-                                  getter_AddRefs(nodeInfo));
+      nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::tr,
+                                   getter_AddRefs(nodeInfo));
 
       newRow = NS_NewHTMLTableRowElement(nodeInfo.forget());
       if (newRow) {
         HTMLTableSectionElement* section =
           static_cast<HTMLTableSectionElement*>(rowGroup.get());
         nsIHTMLCollection* rows = section->Rows();
         nsCOMPtr<nsINode> refNode = rows->Item(0);
         rowGroup->InsertBefore(*newRow, refNode, aError);

--- a/dom/html/HTMLTableElement.h
+++ b/dom/html/HTMLTableElement.h
@@ -31,17 +31,18 @@ public:
   HTMLTableCaptionElement* GetCaption() const
   {
     return static_cast<HTMLTableCaptionElement*>(GetChild(nsGkAtoms::caption));
   }
   void SetCaption(HTMLTableCaptionElement* aCaption, ErrorResult& aError)
   {
     DeleteCaption();
     if (aCaption) {
-      nsINode::AppendChild(*aCaption, aError);
+      nsCOMPtr<nsINode> firstChild = nsINode::GetFirstChild();
+      nsINode::InsertBefore(*aCaption, firstChild, aError);
     }
   }
 
   void DeleteTFoot();
 
   already_AddRefed<nsGenericHTMLElement> CreateCaption();
 
   void DeleteCaption();
@@ -54,17 +55,28 @@ public:
   {
     if (aTHead && !aTHead->IsHTMLElement(nsGkAtoms::thead)) {
       aError.Throw(NS_ERROR_DOM_HIERARCHY_REQUEST_ERR);
       return;
     }
 
     DeleteTHead();
     if (aTHead) {
-      nsCOMPtr<nsINode> refNode = nsINode::GetFirstChild();
+
+      nsCOMPtr<nsIContent> refNode = nullptr;
+      for (refNode = nsINode::GetFirstChild();
+           refNode;
+           refNode = refNode->GetNextSibling()) {
+        if (refNode->IsHTMLElement() &&
+            !refNode->IsHTMLElement(nsGkAtoms::caption) &&
+            !refNode->IsHTMLElement(nsGkAtoms::colgroup)) {
+          break;
+        }
+      }
+
       nsINode::InsertBefore(*aTHead, refNode, aError);
     }
   }
   already_AddRefed<nsGenericHTMLElement> CreateTHead();
 
   void DeleteTHead();
 
   HTMLTableSectionElement* GetTFoot() const

--- a/dom/html/HTMLTableRowElement.cpp
+++ b/dom/html/HTMLTableRowElement.cpp
@@ -170,18 +170,18 @@ HTMLTableRowElement::InsertCell(int32_t 
         aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
         return nullptr;
       }
     }
   }
 
   // create the cell
   RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-  nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::td,
-                              getter_AddRefs(nodeInfo));
+  nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::td,
+                               getter_AddRefs(nodeInfo));
 
   RefPtr<nsGenericHTMLElement> cell =
     NS_NewHTMLTableCellElement(nodeInfo.forget());
   if (!cell) {
     aError.Throw(NS_ERROR_OUT_OF_MEMORY);
     return nullptr;
   }
 

--- a/dom/html/HTMLTableSectionElement.cpp
+++ b/dom/html/HTMLTableSectionElement.cpp
@@ -75,18 +75,18 @@ HTMLTableSectionElement::InsertRow(int32
     aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
     return nullptr;
   }
 
   bool doInsert = (aIndex < int32_t(rowCount)) && (aIndex != -1);
 
   // create the row
   RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-  nsContentUtils::NameChanged(mNodeInfo, nsGkAtoms::tr,
-                              getter_AddRefs(nodeInfo));
+  nsContentUtils::QNameChanged(mNodeInfo, nsGkAtoms::tr,
+                               getter_AddRefs(nodeInfo));
 
   RefPtr<nsGenericHTMLElement> rowContent =
     NS_NewHTMLTableRowElement(nodeInfo.forget());
   if (!rowContent) {
     aError.Throw(NS_ERROR_OUT_OF_MEMORY);
     return nullptr;
   }
 

--- a/dom/ipc/ContentPrefs.cpp
+++ b/dom/ipc/ContentPrefs.cpp
@@ -1,278 +1,279 @@
-/* -*- 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/. */
-
-#include "ContentPrefs.h"
-
-const char* mozilla::dom::ContentPrefs::gInitPrefs[] = {
-  "accessibility.monoaudio.enable",
-  "accessibility.mouse_focuses_formcontrol",
-  "accessibility.tabfocus_applies_to_xul",
-  "app.update.channel",
-  "browser.dom.window.dump.enabled",
-  "browser.sessionhistory.max_entries",
-  "browser.sessionhistory.max_total_viewers",
-  "content.cors.disable",
-  "content.cors.no_private_data",
-  "content.notify.backoffcount",
-  "content.notify.interval",
-  "content.notify.ontimer",
-  "content.sink.enable_perf_mode",
-  "content.sink.event_probe_rate",
-  "content.sink.initial_perf_time",
-  "content.sink.interactive_deflect_count",
-  "content.sink.interactive_parse_time",
-  "content.sink.interactive_time",
-  "content.sink.pending_event_mode",
-  "content.sink.perf_deflect_count",
-  "content.sink.perf_parse_time",
-  "device.storage.prompt.testing",
-  "device.storage.writable.name",
-  "dom.allow_XUL_XBL_for_file",
-  "dom.allow_cut_copy",
-  "dom.enable_frame_timing",
-  "dom.enable_performance",
-  "dom.enable_resource_timing",
-  "dom.event.handling-user-input-time-limit",
-  "dom.event.touch.coalescing.enabled",
-  "dom.forms.autocomplete.experimental",
-  "dom.ipc.processPriorityManager.backgroundGracePeriodMS",
-  "dom.ipc.processPriorityManager.backgroundPerceivableGracePeriodMS",
-  "dom.max_chrome_script_run_time",
-  "dom.max_script_run_time",
-  "dom.mozBrowserFramesEnabled",
-  "dom.performance.enable_notify_performance_timing",
-  "dom.performance.enable_user_timing_logging",
-  "dom.storage.testing",
-  "dom.url.encode_decode_hash",
-  "dom.url.getters_decode_hash",
-  "dom.use_watchdog",
-  "dom.vibrator.enabled",
-  "dom.vibrator.max_vibrate_list_len",
-  "dom.vibrator.max_vibrate_ms",
-  "focusmanager.testmode",
-  "font.size.inflation.disabledInMasterProcess",
-  "font.size.inflation.emPerLine",
-  "font.size.inflation.forceEnabled",
-  "font.size.inflation.lineThreshold",
-  "font.size.inflation.mappingIntercept",
-  "font.size.inflation.maxRatio",
-  "font.size.inflation.minTwips",
-  "full-screen-api.allow-trusted-requests-only",
-  "full-screen-api.enabled",
-  "full-screen-api.unprefix.enabled",
-  "gfx.font_rendering.opentype_svg.enabled",
-  "hangmonitor.timeout",
-  "html5.flushtimer.initialdelay",
-  "html5.flushtimer.subsequentdelay",
-  "html5.offmainthread",
-  "intl.charset.fallback.tld",
-  "intl.ime.hack.on_ime_unaware_apps.fire_key_events_for_composition",
-  "javascript.enabled",
-  "javascript.options.asmjs",
-  "javascript.options.asyncstack",
-  "javascript.options.baselinejit",
-  "javascript.options.baselinejit.threshold",
-  "javascript.options.baselinejit.unsafe_eager_compilation",
-  "javascript.options.discardSystemSource",
-  "javascript.options.dump_stack_on_debuggee_would_run",
-  "javascript.options.gczeal",
-  "javascript.options.gczeal.frequency",
-  "javascript.options.ion",
-  "javascript.options.ion.offthread_compilation",
-  "javascript.options.ion.threshold",
-  "javascript.options.ion.unsafe_eager_compilation",
-  "javascript.options.jit.full_debug_checks",
-  "javascript.options.native_regexp",
-  "javascript.options.parallel_parsing",
-  "javascript.options.shared_memory",
-  "javascript.options.strict",
-  "javascript.options.strict.debug",
-  "javascript.options.throw_on_asmjs_validation_failure",
-  "javascript.options.throw_on_debuggee_would_run",
-  "javascript.options.wasm",
-  "javascript.options.wasm_baselinejit",
-  "javascript.options.werror",
-  "javascript.use_us_english_locale",
-  "jsloader.reuseGlobal",
-  "layout.css.all-shorthand.enabled",
-  "layout.css.background-blend-mode.enabled",
-  "layout.css.background-clip-text.enabled",
-  "layout.css.box-decoration-break.enabled",
-  "layout.css.color-adjust.enabled",
-  "layout.css.contain.enabled",
-  "layout.css.control-characters.visible",
-  "layout.css.display-flow-root.enabled",
-  "layout.css.expensive-style-struct-assertions.enabled",
-  "layout.css.float-logical-values.enabled",
-  "layout.css.font-variations.enabled",
-  "layout.css.grid.enabled",
-  "layout.css.image-orientation.enabled",
-  "layout.css.initial-letter.enabled",
-  "layout.css.isolation.enabled",
-  "layout.css.mix-blend-mode.enabled",
-  "layout.css.object-fit-and-position.enabled",
-  "layout.css.osx-font-smoothing.enabled",
-  "layout.css.overflow-clip-box.enabled",
-  "layout.css.prefixes.animations",
-  "layout.css.prefixes.border-image",
-  "layout.css.prefixes.box-sizing",
-  "layout.css.prefixes.device-pixel-ratio-webkit",
-  "layout.css.prefixes.font-features",
-  "layout.css.prefixes.gradients",
-  "layout.css.prefixes.transforms",
-  "layout.css.prefixes.transitions",
-  "layout.css.prefixes.webkit",
-  "layout.css.scope-pseudo.enabled",
-  "layout.css.scroll-behavior.property-enabled",
-  "layout.css.scroll-snap.enabled",
-  "layout.css.servo.enabled",
-  "layout.css.shape-outside.enabled",
-  "layout.css.text-align-unsafe-value.enabled",
-  "layout.css.text-combine-upright-digits.enabled",
-  "layout.css.text-combine-upright.enabled",
-  "layout.css.touch_action.enabled",
-  "layout.css.unprefixing-service.enabled",
-  "layout.css.unprefixing-service.globally-whitelisted",
-  "layout.css.unprefixing-service.include-test-domains",
-  "layout.css.variables.enabled",
-  "layout.css.visited_links_enabled",
-  "layout.idle_period.required_quiescent_frames",
-  "layout.idle_period.time_limit",
-  "layout.interruptible-reflow.enabled",
-  "mathml.disabled",
-  "media.apple.forcevda",
-  "media.clearkey.persistent-license.enabled",
-  "media.cubeb_latency_msg_frames",
-  "media.cubeb_latency_playback_ms",
-  "media.decoder-doctor.wmf-disabled-is-failure",
-  "media.decoder.fuzzing.dont-delay-inputexhausted",
-  "media.decoder.fuzzing.enabled",
-  "media.decoder.fuzzing.video-output-minimum-interval-ms",
-  "media.decoder.limit",
-  "media.decoder.recycle.enabled",
-  "media.dormant-on-pause-timeout-ms",
-  "media.eme.audio.blank",
-  "media.eme.enabled",
-  "media.eme.video.blank",
-  "media.ffmpeg.enabled",
-  "media.ffvpx.enabled",
-  "media.flac.enabled",
-  "media.forcestereo.enabled",
-  "media.gmp.async-shutdown-timeout",
-  "media.gmp.decoder.aac",
-  "media.gmp.decoder.enabled",
-  "media.gmp.decoder.h264",
-  "media.gmp.insecure.allow",
-  "media.gpu-process-decoder",
-  "media.libavcodec.allow-obsolete",
-  "media.num-decode-threads",
-  "media.ogg.enabled",
-  "media.ogg.flac.enabled",
-  "media.resampling.enabled",
-  "media.resampling.rate",
-  "media.ruin-av-sync.enabled",
-  "media.rust.test_mode",
-  "media.suspend-bkgnd-video.delay-ms",
-  "media.suspend-bkgnd-video.enabled",
-  "media.use-blank-decoder",
-  "media.video_stats.enabled",
-  "media.volume_scale",
-  "media.webspeech.recognition.enable",
-  "media.webspeech.recognition.force_enable",
-  "media.webspeech.synth.force_global_queue",
-  "media.webspeech.test.enable",
-  "media.webspeech.test.fake_fsm_events",
-  "media.webspeech.test.fake_recognition_service",
-  "media.wmf.allow-unsupported-resolutions",
-  "media.wmf.decoder.thread-count",
-  "media.wmf.enabled",
-  "media.wmf.skip-blacklist",
-  "media.wmf.vp9.enabled",
-  "memory.free_dirty_pages",
-  "memory.low_commit_space_threshold_mb",
-  "memory.low_memory_notification_interval_ms",
-  "memory.low_physical_memory_threshold_mb",
-  "memory.low_virtual_mem_threshold_mb",
-  "network.IDN.blacklist_chars",
-  "network.IDN.restriction_profile",
-  "network.IDN.use_whitelist",
-  "network.IDN_show_punycode",
-  "network.buffer.cache.count",
-  "network.buffer.cache.size",
-  "network.captive-portal-service.enabled",
-  "network.cookie.cookieBehavior",
-  "network.cookie.lifetimePolicy",
-  "network.dns.disablePrefetch",
-  "network.dns.disablePrefetchFromHTTPS",
-  "network.jar.block-remote-files",
-  "network.loadinfo.skip_type_assertion",
-  "network.notify.changed",
-  "network.offline-mirrors-connectivity",
-  "network.protocol-handler.external.jar",
-  "network.proxy.type",
-  "network.security.ports.banned",
-  "network.security.ports.banned.override",
-  "network.standard-url.enable-rust",
-  "network.standard-url.max-length",
-  "network.sts.max_time_for_events_between_two_polls",
-  "network.sts.max_time_for_pr_close_during_shutdown",
-  "network.tcp.keepalive.enabled",
-  "network.tcp.keepalive.idle_time",
-  "network.tcp.keepalive.probe_count",
-  "network.tcp.keepalive.retry_interval",
-  "network.tcp.sendbuffer",
-  "nglayout.debug.invalidation",
-  "privacy.donottrackheader.enabled",
-  "privacy.firstparty.isolate",
-  "privacy.firstparty.isolate.restrict_opener_access",
-  "privacy.resistFingerprinting",
-  "security.data_uri.inherit_security_context",
-  "security.fileuri.strict_origin_policy",
-  "security.sandbox.content.level",
-  "security.sandbox.content.tempDirSuffix",
-  "security.sandbox.logging.enabled",
-  "security.sandbox.mac.track.violations",
-  "security.sandbox.windows.log",
-  "security.sandbox.windows.log.stackTraceDepth",
-  "shutdown.watchdog.timeoutSecs",
-  "signed.applets.codebase_principal_support",
-  "svg.disabled",
-  "svg.display-lists.hit-testing.enabled",
-  "svg.display-lists.painting.enabled",
-  "svg.new-getBBox.enabled",
-  "svg.paint-order.enabled",
-  "svg.path-caching.enabled",
-  "svg.transform-box.enabled",
-  "toolkit.asyncshutdown.crash_timeout",
-  "toolkit.asyncshutdown.log",
-  "toolkit.osfile.log",
-  "toolkit.osfile.log.redirect",
-  "toolkit.telemetry.enabled",
-  "toolkit.telemetry.idleTimeout",
-  "toolkit.telemetry.initDelay",
-  "toolkit.telemetry.log.dump",
-  "toolkit.telemetry.log.level",
-  "toolkit.telemetry.minSubsessionLength",
-  "toolkit.telemetry.scheduler.idleTickInterval",
-  "toolkit.telemetry.scheduler.tickInterval",
-  "toolkit.telemetry.unified",
-  "ui.key.menuAccessKeyFocuses",
-  "ui.popup.disable_autohide",
-  "ui.use_activity_cursor",
-  "view_source.editor.external"};
-
-const char** mozilla::dom::ContentPrefs::GetContentPrefs(size_t* aCount)
-{
-  *aCount = ArrayLength(ContentPrefs::gInitPrefs);
-  return gInitPrefs;
-}
-
-const char*  mozilla::dom::ContentPrefs::GetContentPref(size_t aIndex)
-{
-  MOZ_ASSERT(aIndex < ArrayLength(ContentPrefs::gInitPrefs));
-  return gInitPrefs[aIndex];
-}
-
+/* -*- 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/. */
+
+#include "ContentPrefs.h"
+
+const char* mozilla::dom::ContentPrefs::gInitPrefs[] = {
+  "accessibility.monoaudio.enable",
+  "accessibility.mouse_focuses_formcontrol",
+  "accessibility.tabfocus_applies_to_xul",
+  "app.update.channel",
+  "browser.dom.window.dump.enabled",
+  "browser.sessionhistory.max_entries",
+  "browser.sessionhistory.max_total_viewers",
+  "content.cors.disable",
+  "content.cors.no_private_data",
+  "content.notify.backoffcount",
+  "content.notify.interval",
+  "content.notify.ontimer",
+  "content.sink.enable_perf_mode",
+  "content.sink.event_probe_rate",
+  "content.sink.initial_perf_time",
+  "content.sink.interactive_deflect_count",
+  "content.sink.interactive_parse_time",
+  "content.sink.interactive_time",
+  "content.sink.pending_event_mode",
+  "content.sink.perf_deflect_count",
+  "content.sink.perf_parse_time",
+  "device.storage.prompt.testing",
+  "device.storage.writable.name",
+  "dom.allow_XUL_XBL_for_file",
+  "dom.allow_cut_copy",
+  "dom.enable_frame_timing",
+  "dom.enable_performance",
+  "dom.enable_resource_timing",
+  "dom.event.handling-user-input-time-limit",
+  "dom.event.touch.coalescing.enabled",
+  "dom.forms.autocomplete.experimental",
+  "dom.ipc.processPriorityManager.backgroundGracePeriodMS",
+  "dom.ipc.processPriorityManager.backgroundPerceivableGracePeriodMS",
+  "dom.max_chrome_script_run_time",
+  "dom.max_script_run_time",
+  "dom.mozBrowserFramesEnabled",
+  "dom.performance.enable_notify_performance_timing",
+  "dom.performance.enable_user_timing_logging",
+  "dom.storage.testing",
+  "dom.url.encode_decode_hash",
+  "dom.url.getters_decode_hash",
+  "dom.use_watchdog",
+  "dom.vibrator.enabled",
+  "dom.vibrator.max_vibrate_list_len",
+  "dom.vibrator.max_vibrate_ms",
+  "focusmanager.testmode",
+  "font.size.inflation.disabledInMasterProcess",
+  "font.size.inflation.emPerLine",
+  "font.size.inflation.forceEnabled",
+  "font.size.inflation.lineThreshold",
+  "font.size.inflation.mappingIntercept",
+  "font.size.inflation.maxRatio",
+  "font.size.inflation.minTwips",
+  "full-screen-api.allow-trusted-requests-only",
+  "full-screen-api.enabled",
+  "full-screen-api.unprefix.enabled",
+  "gfx.font_rendering.opentype_svg.enabled",
+  "hangmonitor.timeout",
+  "html5.flushtimer.initialdelay",
+  "html5.flushtimer.subsequentdelay",
+  "html5.offmainthread",
+  "intl.charset.fallback.tld",
+  "intl.ime.hack.on_ime_unaware_apps.fire_key_events_for_composition",
+  "javascript.enabled",
+  "javascript.options.asmjs",
+  "javascript.options.asyncstack",
+  "javascript.options.baselinejit",
+  "javascript.options.baselinejit.threshold",
+  "javascript.options.baselinejit.unsafe_eager_compilation",
+  "javascript.options.discardSystemSource",
+  "javascript.options.dump_stack_on_debuggee_would_run",
+  "javascript.options.gczeal",
+  "javascript.options.gczeal.frequency",
+  "javascript.options.ion",
+  "javascript.options.ion.offthread_compilation",
+  "javascript.options.ion.threshold",
+  "javascript.options.ion.unsafe_eager_compilation",
+  "javascript.options.jit.full_debug_checks",
+  "javascript.options.native_regexp",
+  "javascript.options.parallel_parsing",
+  "javascript.options.shared_memory",
+  "javascript.options.strict",
+  "javascript.options.strict.debug",
+  "javascript.options.throw_on_asmjs_validation_failure",
+  "javascript.options.throw_on_debuggee_would_run",
+  "javascript.options.wasm",
+  "javascript.options.wasm_baselinejit",
+  "javascript.options.werror",
+  "javascript.use_us_english_locale",
+  "jsloader.reuseGlobal",
+  "layout.css.all-shorthand.enabled",
+  "layout.css.background-blend-mode.enabled",
+  "layout.css.background-clip-text.enabled",
+  "layout.css.box-decoration-break.enabled",
+  "layout.css.color-adjust.enabled",
+  "layout.css.contain.enabled",
+  "layout.css.control-characters.visible",
+  "layout.css.display-flow-root.enabled",
+  "layout.css.expensive-style-struct-assertions.enabled",
+  "layout.css.float-logical-values.enabled",
+  "layout.css.font-variations.enabled",
+  "layout.css.grid.enabled",
+  "layout.css.image-orientation.enabled",
+  "layout.css.initial-letter.enabled",
+  "layout.css.isolation.enabled",
+  "layout.css.mix-blend-mode.enabled",
+  "layout.css.object-fit-and-position.enabled",
+  "layout.css.osx-font-smoothing.enabled",
+  "layout.css.overflow-clip-box.enabled",
+  "layout.css.prefixes.animations",
+  "layout.css.prefixes.border-image",
+  "layout.css.prefixes.box-sizing",
+  "layout.css.prefixes.device-pixel-ratio-webkit",
+  "layout.css.prefixes.font-features",
+  "layout.css.prefixes.gradients",
+  "layout.css.prefixes.transforms",
+  "layout.css.prefixes.transitions",
+  "layout.css.prefixes.webkit",
+  "layout.css.scope-pseudo.enabled",
+  "layout.css.scroll-behavior.property-enabled",
+  "layout.css.scroll-snap.enabled",
+  "layout.css.servo.enabled",
+  "layout.css.shape-outside.enabled",
+  "layout.css.text-align-unsafe-value.enabled",
+  "layout.css.text-combine-upright-digits.enabled",
+  "layout.css.text-combine-upright.enabled",
+  "layout.css.touch_action.enabled",
+  "layout.css.unprefixing-service.enabled",
+  "layout.css.unprefixing-service.globally-whitelisted",
+  "layout.css.unprefixing-service.include-test-domains",
+  "layout.css.variables.enabled",
+  "layout.css.visited_links_enabled",
+  "layout.idle_period.required_quiescent_frames",
+  "layout.idle_period.time_limit",
+  "layout.interruptible-reflow.enabled",
+  "mathml.disabled",
+  "media.apple.forcevda",
+  "media.clearkey.persistent-license.enabled",
+  "media.cubeb_latency_msg_frames",
+  "media.cubeb_latency_playback_ms",
+  "media.decoder-doctor.wmf-disabled-is-failure",
+  "media.decoder.fuzzing.dont-delay-inputexhausted",
+  "media.decoder.fuzzing.enabled",
+  "media.decoder.fuzzing.video-output-minimum-interval-ms",
+  "media.decoder.limit",
+  "media.decoder.recycle.enabled",
+  "media.dormant-on-pause-timeout-ms",
+  "media.eme.audio.blank",
+  "media.eme.enabled",
+  "media.eme.video.blank",
+  "media.ffmpeg.enabled",
+  "media.ffvpx.enabled",
+  "media.ffvpx.low-latency.enabled",
+  "media.flac.enabled",
+  "media.forcestereo.enabled",
+  "media.gmp.async-shutdown-timeout",
+  "media.gmp.decoder.aac",
+  "media.gmp.decoder.enabled",
+  "media.gmp.decoder.h264",
+  "media.gmp.insecure.allow",
+  "media.gpu-process-decoder",
+  "media.libavcodec.allow-obsolete",
+  "media.num-decode-threads",
+  "media.ogg.enabled",
+  "media.ogg.flac.enabled",
+  "media.resampling.enabled",
+  "media.resampling.rate",
+  "media.ruin-av-sync.enabled",
+  "media.rust.test_mode",
+  "media.suspend-bkgnd-video.delay-ms",
+  "media.suspend-bkgnd-video.enabled",
+  "media.use-blank-decoder",
+  "media.video_stats.enabled",
+  "media.volume_scale",
+  "media.webspeech.recognition.enable",
+  "media.webspeech.recognition.force_enable",
+  "media.webspeech.synth.force_global_queue",
+  "media.webspeech.test.enable",
+  "media.webspeech.test.fake_fsm_events",
+  "media.webspeech.test.fake_recognition_service",
+  "media.wmf.allow-unsupported-resolutions",
+  "media.wmf.decoder.thread-count",
+  "media.wmf.enabled",
+  "media.wmf.skip-blacklist",
+  "media.wmf.vp9.enabled",
+  "memory.free_dirty_pages",
+  "memory.low_commit_space_threshold_mb",
+  "memory.low_memory_notification_interval_ms",
+  "memory.low_physical_memory_threshold_mb",
+  "memory.low_virtual_mem_threshold_mb",
+  "network.IDN.blacklist_chars",
+  "network.IDN.restriction_profile",
+  "network.IDN.use_whitelist",
+  "network.IDN_show_punycode",
+  "network.buffer.cache.count",
+  "network.buffer.cache.size",
+  "network.captive-portal-service.enabled",
+  "network.cookie.cookieBehavior",
+  "network.cookie.lifetimePolicy",
+  "network.dns.disablePrefetch",
+  "network.dns.disablePrefetchFromHTTPS",
+  "network.jar.block-remote-files",
+  "network.loadinfo.skip_type_assertion",
+  "network.notify.changed",
+  "network.offline-mirrors-connectivity",
+  "network.protocol-handler.external.jar",
+  "network.proxy.type",
+  "network.security.ports.banned",
+  "network.security.ports.banned.override",
+  "network.standard-url.enable-rust",
+  "network.standard-url.max-length",
+  "network.sts.max_time_for_events_between_two_polls",
+  "network.sts.max_time_for_pr_close_during_shutdown",
+  "network.tcp.keepalive.enabled",
+  "network.tcp.keepalive.idle_time",
+  "network.tcp.keepalive.probe_count",
+  "network.tcp.keepalive.retry_interval",
+  "network.tcp.sendbuffer",
+  "nglayout.debug.invalidation",
+  "privacy.donottrackheader.enabled",
+  "privacy.firstparty.isolate",
+  "privacy.firstparty.isolate.restrict_opener_access",
+  "privacy.resistFingerprinting",
+  "security.data_uri.inherit_security_context",
+  "security.fileuri.strict_origin_policy",
+  "security.sandbox.content.level",
+  "security.sandbox.content.tempDirSuffix",
+  "security.sandbox.logging.enabled",
+  "security.sandbox.mac.track.violations",
+  "security.sandbox.windows.log",
+  "security.sandbox.windows.log.stackTraceDepth",
+  "shutdown.watchdog.timeoutSecs",
+  "signed.applets.codebase_principal_support",
+  "svg.disabled",
+  "svg.display-lists.hit-testing.enabled",
+  "svg.display-lists.painting.enabled",
+  "svg.new-getBBox.enabled",
+  "svg.paint-order.enabled",
+  "svg.path-caching.enabled",
+  "svg.transform-box.enabled",
+  "toolkit.asyncshutdown.crash_timeout",
+  "toolkit.asyncshutdown.log",
+  "toolkit.osfile.log",
+  "toolkit.osfile.log.redirect",
+  "toolkit.telemetry.enabled",
+  "toolkit.telemetry.idleTimeout",
+  "toolkit.telemetry.initDelay",
+  "toolkit.telemetry.log.dump",
+  "toolkit.telemetry.log.level",
+  "toolkit.telemetry.minSubsessionLength",
+  "toolkit.telemetry.scheduler.idleTickInterval",
+  "toolkit.telemetry.scheduler.tickInterval",
+  "toolkit.telemetry.unified",
+  "ui.key.menuAccessKeyFocuses",
+  "ui.popup.disable_autohide",
+  "ui.use_activity_cursor",
+  "view_source.editor.external"};
+
+const char** mozilla::dom::ContentPrefs::GetContentPrefs(size_t* aCount)
+{
+  *aCount = ArrayLength(ContentPrefs::gInitPrefs);
+  return gInitPrefs;
+}
+
+const char*  mozilla::dom::ContentPrefs::GetContentPref(size_t aIndex)
+{
+  MOZ_ASSERT(aIndex < ArrayLength(ContentPrefs::gInitPrefs));
+  return gInitPrefs[aIndex];
+}
+

--- a/dom/ipc/TabParent.cpp
+++ b/dom/ipc/TabParent.cpp
@@ -2676,20 +2676,26 @@ already_AddRefed<nsILoadContext>
 TabParent::GetLoadContext()
 {
   nsCOMPtr<nsILoadContext> loadContext;
   if (mLoadContext) {
     loadContext = mLoadContext;
   } else {
     bool isPrivate = mChromeFlags & nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW;
     SetPrivateBrowsingAttributes(isPrivate);
+    bool useTrackingProtection = false;
+    nsCOMPtr<nsIDocShell> docShell = mFrameElement->OwnerDoc()->GetDocShell();
+    if (docShell) {
+      docShell->GetUseTrackingProtection(&useTrackingProtection);
+    }
     loadContext = new LoadContext(GetOwnerElement(),
                                   true /* aIsContent */,
                                   isPrivate,
                                   mChromeFlags & nsIWebBrowserChrome::CHROME_REMOTE_WINDOW,
+                                  useTrackingProtection,
                                   OriginAttributesRef());
     mLoadContext = loadContext;
   }
   return loadContext.forget();
 }
 
 NS_IMETHODIMP
 TabParent::GetUseAsyncPanZoom(bool* useAsyncPanZoom)
@@ -2989,17 +2995,18 @@ public:
   NS_IMETHOD GetIsContent(bool*) NO_IMPL
   NS_IMETHOD GetUsePrivateBrowsing(bool*) NO_IMPL
   NS_IMETHOD SetUsePrivateBrowsing(bool) NO_IMPL
   NS_IMETHOD SetPrivateBrowsing(bool) NO_IMPL
   NS_IMETHOD GetIsInIsolatedMozBrowserElement(bool*) NO_IMPL
   NS_IMETHOD GetOriginAttributes(JS::MutableHandleValue) NO_IMPL
   NS_IMETHOD GetUseRemoteTabs(bool*) NO_IMPL
   NS_IMETHOD SetRemoteTabs(bool) NO_IMPL
-  NS_IMETHOD IsTrackingProtectionOn(bool*) NO_IMPL
+  NS_IMETHOD GetUseTrackingProtection(bool*) NO_IMPL
+  NS_IMETHOD SetUseTrackingProtection(bool) NO_IMPL
 #undef NO_IMPL
 
 protected:
   ~FakeChannel() {}
 
   nsCOMPtr<nsIURI> mUri;
   uint64_t mCallbackId;
   nsCOMPtr<Element> mElement;

--- a/dom/media/MediaPrefs.h
+++ b/dom/media/MediaPrefs.h
@@ -116,16 +116,17 @@ private:
   DECL_MEDIA_PREF("media.android-media-codec.preferred",      PDMAndroidMediaCodecPreferred, bool, false);
 #endif
 #ifdef MOZ_FFMPEG
   DECL_MEDIA_PREF("media.ffmpeg.enabled",                     PDMFFmpegEnabled, bool, true);
   DECL_MEDIA_PREF("media.libavcodec.allow-obsolete",          LibavcodecAllowObsolete, bool, false);
 #endif
 #ifdef MOZ_FFVPX
   DECL_MEDIA_PREF("media.ffvpx.enabled",                      PDMFFVPXEnabled, bool, true);
+  DECL_MEDIA_PREF("media.ffvpx.low-latency.enabled",          PDMFFVPXLowLatencyEnabled, bool, false);
 #endif
 #ifdef XP_WIN
   DECL_MEDIA_PREF("media.wmf.enabled",                        PDMWMFEnabled, bool, true);
   DECL_MEDIA_PREF("media.wmf.skip-blacklist",                 PDMWMFSkipBlacklist, bool, false);
   DECL_MEDIA_PREF("media.decoder-doctor.wmf-disabled-is-failure", DecoderDoctorWMFDisabledIsFailure, bool, false);
   DECL_MEDIA_PREF("media.wmf.vp9.enabled",                    PDMWMFVP9DecoderEnabled, bool, true);
   DECL_MEDIA_PREF("media.wmf.decoder.thread-count",           PDMWMFThreadCount, int32_t, -1);
   DECL_MEDIA_PREF("media.wmf.allow-unsupported-resolutions",  PDMWMFAllowUnsupportedResolutions, bool, false);

--- a/dom/media/gmp/GMPCrashHelper.h
+++ b/dom/media/gmp/GMPCrashHelper.h
@@ -2,18 +2,19 @@
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* 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/. */
 
 #if !defined(GMPCrashHelper_h_)
 #define GMPCrashHelper_h_
 
+#include "MainThreadUtils.h"
+#include "nsISupportsImpl.h"
 #include "nsPIDOMWindow.h"
-#include "nsISupportsImpl.h"
 
 namespace mozilla {
 
 // For every GMP actor requested, the caller can specify a crash helper,
 // which is an object which supplies the nsPIDOMWindowInner to which we'll
 // dispatch the PluginCrashed event if the GMP crashes.
 // GMPCrashHelper has threadsafe refcounting. Its release method ensures
 // that instances are destroyed on the main thread.

--- a/dom/media/ipc/PVideoDecoder.ipdl
+++ b/dom/media/ipc/PVideoDecoder.ipdl
@@ -21,16 +21,17 @@ struct MediaDataIPDL
   uint32_t frames;
   bool keyframe;
 };
 
 struct VideoDataIPDL
 {
   MediaDataIPDL base;
   IntSize display;
+  IntSize frameSize;
   SurfaceDescriptorGPUVideo sd;
   int32_t frameID;
 };
 
 struct MediaRawDataIPDL
 {
   MediaDataIPDL base;
   Shmem buffer;

--- a/dom/media/ipc/VideoDecoderChild.cpp
+++ b/dom/media/ipc/VideoDecoderChild.cpp
@@ -39,17 +39,17 @@ mozilla::ipc::IPCResult
 VideoDecoderChild::RecvOutput(const VideoDataIPDL& aData)
 {
   AssertOnManagerThread();
   VideoInfo info(aData.display().width, aData.display().height);
 
   // The Image here creates a TextureData object that takes ownership
   // of the SurfaceDescriptor, and is responsible for making sure that
   // it gets deallocated.
-  RefPtr<Image> image = new GPUVideoImage(GetManager(), aData.sd(), aData.display());
+  RefPtr<Image> image = new GPUVideoImage(GetManager(), aData.sd(), aData.frameSize());
 
   RefPtr<VideoData> video = VideoData::CreateFromImage(info,
                                                        aData.base().offset(),
                                                        aData.base().time(),
                                                        aData.base().duration(),
                                                        image,
                                                        aData.base().keyframe(),
                                                        aData.base().timecode(),

--- a/dom/media/ipc/VideoDecoderParent.cpp
+++ b/dom/media/ipc/VideoDecoderParent.cpp
@@ -184,16 +184,17 @@ VideoDecoderParent::ProcessDecodedData(
       texture->InitIPDLActor(mKnowsCompositor);
       texture->SetAddedToCompositableClient();
     }
 
     VideoDataIPDL output(
       MediaDataIPDL(data->mOffset, data->mTime, data->mTimecode,
                     data->mDuration, data->mFrames, data->mKeyframe),
       video->mDisplay,
+      texture ? texture->GetSize() : IntSize(),
       texture ? mParent->StoreImage(video->mImage, texture)
               : SurfaceDescriptorGPUVideo(0),
       video->mFrameID);
     Unused << SendOutput(output);
   }
 }
 
 mozilla::ipc::IPCResult

--- a/dom/media/mediasource/MediaSource.cpp
+++ b/dom/media/mediasource/MediaSource.cpp
@@ -110,16 +110,18 @@ MediaSource::IsTypeSupported(const nsASt
       mimeType == MEDIAMIMETYPE("audio/mp4")) {
     if (!Preferences::GetBool("media.mediasource.mp4.enabled", false)) {
       return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
     }
     return NS_OK;
   }
   if (mimeType == MEDIAMIMETYPE("video/webm")) {
     if (!(Preferences::GetBool("media.mediasource.webm.enabled", false) ||
+          containerType->ExtendedType().Codecs().Contains(
+            NS_LITERAL_STRING("vp8")) ||
           IsWebMForced(aDiagnostics))) {
       return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
     }
     return NS_OK;
   }
   if (mimeType == MEDIAMIMETYPE("audio/webm")) {
     if (!(Preferences::GetBool("media.mediasource.webm.enabled", false) ||
           Preferences::GetBool("media.mediasource.webm.audio.enabled", true))) {

--- a/dom/media/mediasource/test/test_MediaSource.html
+++ b/dom/media/mediasource/test/test_MediaSource.html
@@ -35,16 +35,19 @@ runWithMSE(function () {
   v.src = o;
   document.body.appendChild(v);
 
   var loadedmetadataCount = 0;
   var updatestartCount = 0;
   var updateendCount = 0;
   var updateCount = 0;
 
+  ok(MediaSource.isTypeSupported("video/webm; codecs=vp8"), "VP8 MSE is always supported");
+  ok(MediaSource.isTypeSupported("audio/webm", "Audio MSE is always supported"));
+
   ms.addEventListener("sourceopen", function () {
     ok(true, "Receive a sourceopen event");
     is(ms.readyState, "open", "MediaSource must be in open state after sourceopen");
     var sb = ms.addSourceBuffer("video/webm");
     ok(sb, "Create a SourceBuffer");
     is(ms.sourceBuffers.length, 1, "MediaSource.sourceBuffers is expected length");
     is(ms.sourceBuffers[0], sb, "SourceBuffer in list matches our SourceBuffer");
     is(ms.activeSourceBuffers.length, 0, "MediaSource.activeSourceBuffers is expected length");

--- a/dom/media/platforms/PlatformDecoderModule.h
+++ b/dom/media/platforms/PlatformDecoderModule.h
@@ -2,26 +2,27 @@
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* 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/. */
 
 #if !defined(PlatformDecoderModule_h_)
 #define PlatformDecoderModule_h_
 
+#include "GMPCrashHelper.h"
 #include "MediaDecoderReader.h"
 #include "MediaInfo.h"
+#include "MediaResult.h"
+#include "mozilla/EnumSet.h"
 #include "mozilla/MozPromise.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/layers/KnowsCompositor.h"
 #include "mozilla/layers/LayersTypes.h"
-#include "mozilla/layers/KnowsCompositor.h"
 #include "nsTArray.h"
-#include "mozilla/RefPtr.h"
-#include "GMPCrashHelper.h"
 #include <queue>
-#include "MediaResult.h"
 
 namespace mozilla {
 class TrackInfo;
 class AudioInfo;
 class VideoInfo;
 class MediaRawData;
 class DecoderDoctorDiagnostics;
 
@@ -36,20 +37,24 @@ class RemoteDecoderModule;
 class MediaDataDecoder;
 class TaskQueue;
 class CDMProxy;
 
 static LazyLogModule sPDMLog("PlatformDecoderModule");
 
 struct MOZ_STACK_CLASS CreateDecoderParams final
 {
-  explicit CreateDecoderParams(const TrackInfo& aConfig)
-    : mConfig(aConfig)
+  explicit CreateDecoderParams(const TrackInfo& aConfig) : mConfig(aConfig) { }
+
+  enum class Option
   {
-  }
+    Default,
+    LowLatency,
+  };
+  using OptionSet = EnumSet<Option>;
 
   template <typename T1, typename... Ts>
   CreateDecoderParams(const TrackInfo& aConfig, T1&& a1, Ts&&... args)
     : mConfig(aConfig)
   {
     Set(mozilla::Forward<T1>(a1), mozilla::Forward<Ts>(args)...);
   }
 
@@ -78,30 +83,32 @@ struct MOZ_STACK_CLASS CreateDecoderPara
   DecoderDoctorDiagnostics* mDiagnostics = nullptr;
   layers::ImageContainer* mImageContainer = nullptr;
   MediaResult* mError = nullptr;
   RefPtr<layers::KnowsCompositor> mKnowsCompositor;
   RefPtr<GMPCrashHelper> mCrashHelper;
   bool mUseBlankDecoder = false;
   TrackInfo::TrackType mType = TrackInfo::kUndefinedTrack;
   MediaEventProducer<TrackInfo::TrackType>* mOnWaitingForKeyEvent = nullptr;
+  OptionSet mOptions = OptionSet(Option::Default);
 
 private:
   void Set(TaskQueue* aTaskQueue) { mTaskQueue = aTaskQueue; }
   void Set(DecoderDoctorDiagnostics* aDiagnostics)
   {
     mDiagnostics = aDiagnostics;
   }
   void Set(layers::ImageContainer* aImageContainer)
   {
     mImageContainer = aImageContainer;
   }
   void Set(MediaResult* aError) { mError = aError; }
   void Set(GMPCrashHelper* aCrashHelper) { mCrashHelper = aCrashHelper; }
   void Set(bool aUseBlankDecoder) { mUseBlankDecoder = aUseBlankDecoder; }
+  void Set(OptionSet aOptions) { mOptions = aOptions; }
   void Set(layers::KnowsCompositor* aKnowsCompositor)
   {
     mKnowsCompositor = aKnowsCompositor;
   }
   void Set(TrackInfo::TrackType aType)
   {
     mType = aType;
   }
@@ -133,24 +140,25 @@ private:
 
 class PlatformDecoderModule
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(PlatformDecoderModule)
 
   // Perform any per-instance initialization.
   // This is called on the decode task queue.
-  virtual nsresult Startup() { return NS_OK; };
+  virtual nsresult Startup() { return NS_OK; }
 
   // Indicates if the PlatformDecoderModule supports decoding of aMimeType.
-  virtual bool SupportsMimeType(
-    const nsACString& aMimeType,
-    DecoderDoctorDiagnostics* aDiagnostics) const = 0;
-  virtual bool Supports(const TrackInfo& aTrackInfo,
-                        DecoderDoctorDiagnostics* aDiagnostics) const
+  virtual bool
+  SupportsMimeType(const nsACString& aMimeType,
+                   DecoderDoctorDiagnostics* aDiagnostics) const = 0;
+  virtual bool
+  Supports(const TrackInfo& aTrackInfo,
+           DecoderDoctorDiagnostics* aDiagnostics) const
   {
     // By default, fall back to SupportsMimeType with just the MIME string.
     // (So PDMs do not need to override this method -- yet.)
     return SupportsMimeType(aTrackInfo.mMimeType, aDiagnostics);
   }
 
 protected:
   PlatformDecoderModule() { }
@@ -202,17 +210,17 @@ protected:
 //
 // Decoding is done asynchronously. Any async work can be done on the
 // TaskQueue passed into the PlatformDecoderModules's Create*Decoder()
 // function. This may not be necessary for platforms with async APIs
 // for decoding.
 class MediaDataDecoder
 {
 protected:
-  virtual ~MediaDataDecoder() {};
+  virtual ~MediaDataDecoder() { }
 
 public:
   typedef TrackInfo::TrackType TrackType;
   typedef nsTArray<RefPtr<MediaData>> DecodedData;
   typedef MozPromise<TrackType, MediaResult, /* IsExclusive = */ true>
     InitPromise;
   typedef MozPromise<DecodedData, MediaResult, /* IsExclusive = */ true>
     DecodePromise;
@@ -276,17 +284,17 @@ public:
   virtual const char* GetDescriptionName() const = 0;
 
   // Set a hint of seek target time to decoder. Decoder will drop any decoded
   // data which pts is smaller than this value. This threshold needs to be clear
   // after reset decoder.
   // Decoder may not honor this value. However, it'd be better that
   // video decoder implements this API to improve seek performance.
   // Note: it should be called before Input() or after Flush().
-  virtual void SetSeekThreshold(const media::TimeUnit& aTime) {}
+  virtual void SetSeekThreshold(const media::TimeUnit& aTime) { }
 
   // When playing adaptive playback, recreating an Android video decoder will
   // cause the transition not smooth during resolution change.
   // Reuse the decoder if the decoder support recycling.
   // Currently, only Android video decoder will return true.
   virtual bool SupportDecoderRecycling() const { return false; }
 
   // ConfigurationChanged will be called to inform the video or audio decoder