Add m-esr52 at 52.6.0

1 files changed, 1175 insertions, 0 deletions

diff --git a/dom/base/nsDOMMutationObserver.cpp b/dom/base/nsDOMMutationObserver.cpp
new file mode 100644
index 000000000..024ce5e2e
--- /dev/null
+++ b/dom/base/nsDOMMutationObserver.cpp
@@ -0,0 +1,1175 @@
+/* -*- 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 "nsDOMMutationObserver.h"
+
+#include "mozilla/AnimationTarget.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/OwningNonNull.h"
+
+#include "mozilla/dom/Animation.h"
+#include "mozilla/dom/KeyframeEffectReadOnly.h"
+
+#include "nsContentUtils.h"
+#include "nsCSSPseudoElements.h"
+#include "nsError.h"
+#include "nsIDOMMutationEvent.h"
+#include "nsIScriptGlobalObject.h"
+#include "nsServiceManagerUtils.h"
+#include "nsTextFragment.h"
+#include "nsThreadUtils.h"
+
+using mozilla::Maybe;
+using mozilla::Move;
+using mozilla::NonOwningAnimationTarget;
+using mozilla::dom::TreeOrderComparator;
+using mozilla::dom::Animation;
+using mozilla::dom::Element;
+
+AutoTArray<RefPtr<nsDOMMutationObserver>, 4>*
+  nsDOMMutationObserver::sScheduledMutationObservers = nullptr;
+
+nsDOMMutationObserver* nsDOMMutationObserver::sCurrentObserver = nullptr;
+
+uint32_t nsDOMMutationObserver::sMutationLevel = 0;
+uint64_t nsDOMMutationObserver::sCount = 0;
+
+AutoTArray<AutoTArray<RefPtr<nsDOMMutationObserver>, 4>, 4>*
+nsDOMMutationObserver::sCurrentlyHandlingObservers = nullptr;
+
+nsINodeList*
+nsDOMMutationRecord::AddedNodes()
+{
+  if (!mAddedNodes) {
+    mAddedNodes = new nsSimpleContentList(mTarget);
+  }
+  return mAddedNodes;
+}
+
+nsINodeList*
+nsDOMMutationRecord::RemovedNodes()
+{
+  if (!mRemovedNodes) {
+    mRemovedNodes = new nsSimpleContentList(mTarget);
+  }
+  return mRemovedNodes;
+}
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMMutationRecord)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMMutationRecord)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMMutationRecord)
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(nsDOMMutationRecord,
+                                      mTarget,
+                                      mPreviousSibling, mNextSibling,
+                                      mAddedNodes, mRemovedNodes,
+                                      mAddedAnimations, mRemovedAnimations,
+                                      mChangedAnimations,
+                                      mNext, mOwner)
+
+// Observer
+
+bool
+nsMutationReceiverBase::IsObservable(nsIContent* aContent)
+{
+  return !aContent->ChromeOnlyAccess() &&
+    (Observer()->IsChrome() || !aContent->IsInAnonymousSubtree());
+}
+
+NS_IMPL_ADDREF(nsMutationReceiver)
+NS_IMPL_RELEASE(nsMutationReceiver)
+
+NS_INTERFACE_MAP_BEGIN(nsMutationReceiver)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
+NS_INTERFACE_MAP_END
+
+nsMutationReceiver::nsMutationReceiver(nsINode* aTarget,
+                                       nsDOMMutationObserver* aObserver)
+: nsMutationReceiverBase(aTarget, aObserver)
+{
+  mTarget->BindObject(aObserver);
+}
+
+void
+nsMutationReceiver::Disconnect(bool aRemoveFromObserver)
+{
+  if (mRegisterTarget) {
+    mRegisterTarget->RemoveMutationObserver(this);
+    mRegisterTarget = nullptr;
+  }
+
+  mParent = nullptr;
+  nsINode* target = mTarget;
+  mTarget = nullptr;
+  nsDOMMutationObserver* observer = mObserver;
+  mObserver = nullptr;
+  RemoveClones();
+
+  if (target && observer) {
+    if (aRemoveFromObserver) {
+      static_cast<nsDOMMutationObserver*>(observer)->RemoveReceiver(this);
+    }
+    // UnbindObject may delete 'this'!
+    target->UnbindObject(observer);
+  }
+}
+
+void
+nsMutationReceiver::NativeAnonymousChildListChange(nsIDocument* aDocument,
+                                                   nsIContent* aContent,
+                                                   bool aIsRemove) {
+  if (!NativeAnonymousChildList()) {
+    return;
+  }
+
+  nsINode* parent = aContent->GetParentNode();
+  if (!parent ||
+      (!Subtree() && Target() != parent) ||
+      (Subtree() && RegisterTarget()->SubtreeRoot() != parent->SubtreeRoot())) {
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::nativeAnonymousChildList);
+
+  if (m->mTarget) {
+    return;
+  }
+  m->mTarget = parent;
+
+  if (aIsRemove) {
+    m->mRemovedNodes = new nsSimpleContentList(parent);
+    m->mRemovedNodes->AppendElement(aContent);
+  } else {
+    m->mAddedNodes = new nsSimpleContentList(parent);
+    m->mAddedNodes->AppendElement(aContent);
+  }
+}
+
+void
+nsMutationReceiver::AttributeWillChange(nsIDocument* aDocument,
+                                        mozilla::dom::Element* aElement,
+                                        int32_t aNameSpaceID,
+                                        nsIAtom* aAttribute,
+                                        int32_t aModType,
+                                        const nsAttrValue* aNewValue)
+{
+  if (nsAutoMutationBatch::IsBatching() ||
+      !ObservesAttr(RegisterTarget(), aElement, aNameSpaceID, aAttribute)) {
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::attributes);
+
+  NS_ASSERTION(!m->mTarget || m->mTarget == aElement,
+               "Wrong target!");
+  NS_ASSERTION(!m->mAttrName || m->mAttrName == aAttribute,
+               "Wrong attribute!");
+  if (!m->mTarget) {
+    m->mTarget = aElement;
+    m->mAttrName = aAttribute;
+    if (aNameSpaceID == kNameSpaceID_None) {
+      m->mAttrNamespace.SetIsVoid(true);
+    } else {
+      nsContentUtils::NameSpaceManager()->GetNameSpaceURI(aNameSpaceID,
+                                                          m->mAttrNamespace);
+    }
+  }
+
+  if (AttributeOldValue() && m->mPrevValue.IsVoid()) {
+    if (!aElement->GetAttr(aNameSpaceID, aAttribute, m->mPrevValue)) {
+      m->mPrevValue.SetIsVoid(true);
+    }
+  }
+}
+
+void
+nsMutationReceiver::CharacterDataWillChange(nsIDocument *aDocument,
+                                            nsIContent* aContent,
+                                            CharacterDataChangeInfo* aInfo)
+{
+  if (nsAutoMutationBatch::IsBatching() ||
+      !CharacterData() ||
+      (!Subtree() && aContent != Target()) ||
+      (Subtree() && RegisterTarget()->SubtreeRoot() != aContent->SubtreeRoot()) ||
+      !IsObservable(aContent)) {
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::characterData);
+
+  NS_ASSERTION(!m->mTarget || m->mTarget == aContent,
+               "Wrong target!");
+
+  if (!m->mTarget) {
+    m->mTarget = aContent;
+  }
+  if (CharacterDataOldValue() && m->mPrevValue.IsVoid()) { 
+    aContent->GetText()->AppendTo(m->mPrevValue);
+  }
+}
+
+void
+nsMutationReceiver::ContentAppended(nsIDocument* aDocument,
+                                    nsIContent* aContainer,
+                                    nsIContent* aFirstNewContent,
+                                    int32_t aNewIndexInContainer)
+{
+  nsINode* parent = NODE_FROM(aContainer, aDocument);
+  bool wantsChildList =
+    ChildList() &&
+    ((Subtree() && RegisterTarget()->SubtreeRoot() == parent->SubtreeRoot()) ||
+     parent == Target());
+  if (!wantsChildList || !IsObservable(aFirstNewContent)) {
+    return;
+  }
+
+  if (nsAutoMutationBatch::IsBatching()) {
+    if (parent == nsAutoMutationBatch::GetBatchTarget()) {
+      nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
+    }
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::childList);
+  NS_ASSERTION(!m->mTarget || m->mTarget == parent,
+               "Wrong target!");
+  if (m->mTarget) {
+    // Already handled case.
+    return;
+  }
+  m->mTarget = parent;
+  m->mAddedNodes = new nsSimpleContentList(parent);
+
+  nsINode* n = aFirstNewContent;
+  while (n) {
+    m->mAddedNodes->AppendElement(static_cast<nsIContent*>(n));
+    n = n->GetNextSibling();
+  }
+  m->mPreviousSibling = aFirstNewContent->GetPreviousSibling();
+}
+
+void
+nsMutationReceiver::ContentInserted(nsIDocument* aDocument,
+                                    nsIContent* aContainer,
+                                    nsIContent* aChild,
+                                    int32_t aIndexInContainer)
+{
+  nsINode* parent = NODE_FROM(aContainer, aDocument);
+  bool wantsChildList =
+    ChildList() &&
+    ((Subtree() && RegisterTarget()->SubtreeRoot() == parent->SubtreeRoot()) ||
+     parent == Target());
+  if (!wantsChildList || !IsObservable(aChild)) {
+    return;
+  }
+
+  if (nsAutoMutationBatch::IsBatching()) {
+    if (parent == nsAutoMutationBatch::GetBatchTarget()) {
+      nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
+    }
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::childList);
+  if (m->mTarget) {
+    // Already handled case.
+    return;  
+  }
+  m->mTarget = parent;
+  m->mAddedNodes = new nsSimpleContentList(parent);
+  m->mAddedNodes->AppendElement(aChild);
+  m->mPreviousSibling = aChild->GetPreviousSibling();
+  m->mNextSibling = aChild->GetNextSibling();
+}
+
+void
+nsMutationReceiver::ContentRemoved(nsIDocument* aDocument,
+                                   nsIContent* aContainer,
+                                   nsIContent* aChild,
+                                   int32_t aIndexInContainer,
+                                   nsIContent* aPreviousSibling)
+{
+  if (!IsObservable(aChild)) {
+    return;
+  }
+
+  nsINode* parent = NODE_FROM(aContainer, aDocument);
+  if (Subtree() && parent->SubtreeRoot() != RegisterTarget()->SubtreeRoot()) {
+    return;
+  }
+  if (nsAutoMutationBatch::IsBatching()) {
+    if (nsAutoMutationBatch::IsRemovalDone()) {
+      // This can happen for example if HTML parser parses to
+      // context node, but needs to move elements around.
+      return;
+    }
+    if (nsAutoMutationBatch::GetBatchTarget() != parent) {
+      return;
+    }
+
+    bool wantsChildList = ChildList() && (Subtree() || parent == Target());
+    if (wantsChildList || Subtree()) {
+      nsAutoMutationBatch::NodeRemoved(aChild);
+      nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
+    }
+
+    return;
+  }
+
+  if (Subtree()) {
+    // Try to avoid creating transient observer if the node
+    // already has an observer observing the same set of nodes.
+    nsMutationReceiver* orig = GetParent() ? GetParent() : this;
+    if (Observer()->GetReceiverFor(aChild, false, false) != orig) {
+      bool transientExists = false;
+      nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
+      Observer()->mTransientReceivers.Get(aChild, &transientReceivers);
+      if (!transientReceivers) {
+        transientReceivers = new nsCOMArray<nsMutationReceiver>();
+        Observer()->mTransientReceivers.Put(aChild, transientReceivers);
+      } else {
+        for (int32_t i = 0; i < transientReceivers->Count(); ++i) {
+          nsMutationReceiver* r = transientReceivers->ObjectAt(i);
+          if (r->GetParent() == orig) {
+            transientExists = true;
+          }
+        }
+      }
+      if (!transientExists) {
+        // Make sure the elements which are removed from the
+        // subtree are kept in the same observation set.
+        nsMutationReceiver* tr;
+        if (orig->Animations()) {
+          tr = nsAnimationReceiver::Create(aChild, orig);
+        } else {
+          tr = nsMutationReceiver::Create(aChild, orig);
+        }
+        transientReceivers->AppendObject(tr);
+      }
+    }
+  }
+
+  if (ChildList() && (Subtree() || parent == Target())) {
+    nsDOMMutationRecord* m =
+      Observer()->CurrentRecord(nsGkAtoms::childList);
+    if (m->mTarget) {
+      // Already handled case.
+      return;
+    }
+    m->mTarget = parent;
+    m->mRemovedNodes = new nsSimpleContentList(parent);
+    m->mRemovedNodes->AppendElement(aChild);
+    m->mPreviousSibling = aPreviousSibling;
+    m->mNextSibling = parent->GetChildAt(aIndexInContainer);
+  }
+  // We need to schedule always, so that after microtask mTransientReceivers
+  // can be cleared correctly.
+  Observer()->ScheduleForRun();
+}
+
+void nsMutationReceiver::NodeWillBeDestroyed(const nsINode *aNode)
+{
+  NS_ASSERTION(!mParent, "Shouldn't have mParent here!");
+  Disconnect(true);
+}
+
+void
+nsAnimationReceiver::RecordAnimationMutation(Animation* aAnimation,
+                                             AnimationMutation aMutationType)
+{
+  mozilla::dom::AnimationEffectReadOnly* effect = aAnimation->GetEffect();
+  if (!effect) {
+    return;
+  }
+
+  mozilla::dom::KeyframeEffectReadOnly* keyframeEffect =
+    effect->AsKeyframeEffect();
+  if (!keyframeEffect) {
+    return;
+  }
+
+  Maybe<NonOwningAnimationTarget> animationTarget = keyframeEffect->GetTarget();
+  if (!animationTarget) {
+    return;
+  }
+
+  Element* elem = animationTarget->mElement;
+  if (!Animations() || !(Subtree() || elem == Target()) ||
+      elem->ChromeOnlyAccess()) {
+    return;
+  }
+
+  // Record animations targeting to a pseudo element only when subtree is true.
+  if (animationTarget->mPseudoType != mozilla::CSSPseudoElementType::NotPseudo &&
+      !Subtree()) {
+    return;
+  }
+
+  if (nsAutoAnimationMutationBatch::IsBatching()) {
+    switch (aMutationType) {
+      case eAnimationMutation_Added:
+        nsAutoAnimationMutationBatch::AnimationAdded(aAnimation, elem);
+        break;
+      case eAnimationMutation_Changed:
+        nsAutoAnimationMutationBatch::AnimationChanged(aAnimation, elem);
+        break;
+      case eAnimationMutation_Removed:
+        nsAutoAnimationMutationBatch::AnimationRemoved(aAnimation, elem);
+        break;
+    }
+
+    nsAutoAnimationMutationBatch::AddObserver(Observer());
+    return;
+  }
+
+  nsDOMMutationRecord* m =
+    Observer()->CurrentRecord(nsGkAtoms::animations);
+
+  NS_ASSERTION(!m->mTarget, "Wrong target!");
+
+  m->mTarget = elem;
+
+  switch (aMutationType) {
+    case eAnimationMutation_Added:
+      m->mAddedAnimations.AppendElement(aAnimation);
+      break;
+    case eAnimationMutation_Changed:
+      m->mChangedAnimations.AppendElement(aAnimation);
+      break;
+    case eAnimationMutation_Removed:
+      m->mRemovedAnimations.AppendElement(aAnimation);
+      break;
+  }
+}
+
+void
+nsAnimationReceiver::AnimationAdded(Animation* aAnimation)
+{
+  RecordAnimationMutation(aAnimation, eAnimationMutation_Added);
+}
+
+void
+nsAnimationReceiver::AnimationChanged(Animation* aAnimation)
+{
+  RecordAnimationMutation(aAnimation, eAnimationMutation_Changed);
+}
+
+void
+nsAnimationReceiver::AnimationRemoved(Animation* aAnimation)
+{
+  RecordAnimationMutation(aAnimation, eAnimationMutation_Removed);
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(nsAnimationReceiver, nsMutationReceiver,
+                            nsIAnimationObserver)
+
+// Observer
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMMutationObserver)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsDOMMutationObserver)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMMutationObserver)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMMutationObserver)
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsDOMMutationObserver)
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsDOMMutationObserver)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsDOMMutationObserver)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOwner)
+  for (int32_t i = 0; i < tmp->mReceivers.Count(); ++i) {
+    tmp->mReceivers[i]->Disconnect(false);
+  }
+  tmp->mReceivers.Clear();
+  tmp->ClearPendingRecords();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCallback)
+  // No need to handle mTransientReceivers
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsDOMMutationObserver)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwner)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mReceivers)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFirstPendingMutation)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallback)
+  // No need to handle mTransientReceivers
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+nsMutationReceiver*
+nsDOMMutationObserver::GetReceiverFor(nsINode* aNode, bool aMayCreate,
+                                      bool aWantsAnimations)
+{
+  MOZ_ASSERT(aMayCreate || !aWantsAnimations,
+             "the value of aWantsAnimations doesn't matter when aMayCreate is "
+             "false, so just pass in false for it");
+
+  if (!aMayCreate && !aNode->MayHaveDOMMutationObserver()) {
+    return nullptr;
+  }
+
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    if (mReceivers[i]->Target() == aNode) {
+      return mReceivers[i];
+    }
+  }
+  if (!aMayCreate) {
+    return nullptr;
+  }
+
+  nsMutationReceiver* r;
+  if (aWantsAnimations) {
+    r = nsAnimationReceiver::Create(aNode, this);
+  } else {
+    r = nsMutationReceiver::Create(aNode, this);
+  }
+  mReceivers.AppendObject(r);
+  return r;
+}
+
+void
+nsDOMMutationObserver::RemoveReceiver(nsMutationReceiver* aReceiver)
+{
+  mReceivers.RemoveObject(aReceiver);
+}
+
+void
+nsDOMMutationObserver::GetAllSubtreeObserversFor(nsINode* aNode,
+                                                 nsTArray<nsMutationReceiver*>&
+                                                   aReceivers)
+{
+  nsINode* n = aNode;
+  while (n) {
+    if (n->MayHaveDOMMutationObserver()) {
+      nsMutationReceiver* r = GetReceiverFor(n, false, false);
+      if (r && r->Subtree() && !aReceivers.Contains(r)) {
+        aReceivers.AppendElement(r);
+        // If we've found all the receivers the observer has,
+        // no need to search for more.
+        if (mReceivers.Count() == int32_t(aReceivers.Length())) {
+          return;
+        }
+      }                                            
+      nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
+      if (mTransientReceivers.Get(n, &transientReceivers) && transientReceivers) {
+        for (int32_t i = 0; i < transientReceivers->Count(); ++i) {
+          nsMutationReceiver* r = transientReceivers->ObjectAt(i);
+          nsMutationReceiver* parent = r->GetParent();
+          if (r->Subtree() && parent && !aReceivers.Contains(parent)) {
+            aReceivers.AppendElement(parent);
+          }
+        }
+        if (mReceivers.Count() == int32_t(aReceivers.Length())) {
+          return;
+        }
+      }
+    }
+    n = n->GetParentNode();
+  }
+}
+
+void
+nsDOMMutationObserver::ScheduleForRun()
+{
+  nsDOMMutationObserver::AddCurrentlyHandlingObserver(this, sMutationLevel);
+
+  if (mWaitingForRun) {
+    return;
+  }
+  mWaitingForRun = true;
+  RescheduleForRun();
+}
+
+void
+nsDOMMutationObserver::RescheduleForRun()
+{
+  if (!sScheduledMutationObservers) {
+    sScheduledMutationObservers = new AutoTArray<RefPtr<nsDOMMutationObserver>, 4>;
+  }
+
+  bool didInsert = false;
+  for (uint32_t i = 0; i < sScheduledMutationObservers->Length(); ++i) {
+    if (static_cast<nsDOMMutationObserver*>((*sScheduledMutationObservers)[i])
+          ->mId > mId) {
+      sScheduledMutationObservers->InsertElementAt(i, this);
+      didInsert = true;
+      break;
+    }
+  }
+  if (!didInsert) {
+    sScheduledMutationObservers->AppendElement(this);
+  }
+}
+
+void
+nsDOMMutationObserver::Observe(nsINode& aTarget,
+                               const mozilla::dom::MutationObserverInit& aOptions,
+                               mozilla::ErrorResult& aRv)
+{
+
+  bool childList = aOptions.mChildList;
+  bool attributes =
+    aOptions.mAttributes.WasPassed() &&
+    aOptions.mAttributes.Value();
+  bool characterData =
+    aOptions.mCharacterData.WasPassed() &&
+    aOptions.mCharacterData.Value();
+  bool subtree = aOptions.mSubtree;
+  bool attributeOldValue =
+    aOptions.mAttributeOldValue.WasPassed() &&
+    aOptions.mAttributeOldValue.Value();
+  bool nativeAnonymousChildList = aOptions.mNativeAnonymousChildList;
+  bool characterDataOldValue =
+    aOptions.mCharacterDataOldValue.WasPassed() &&
+    aOptions.mCharacterDataOldValue.Value();
+  bool animations = aOptions.mAnimations;
+
+  if (!aOptions.mAttributes.WasPassed() &&
+      (aOptions.mAttributeOldValue.WasPassed() ||
+       aOptions.mAttributeFilter.WasPassed())) {
+    attributes = true;
+  }
+
+  if (!aOptions.mCharacterData.WasPassed() &&
+      aOptions.mCharacterDataOldValue.WasPassed()) {
+    characterData = true;
+  }
+
+  if (!(childList || attributes || characterData || animations ||
+        nativeAnonymousChildList)) {
+    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
+    return;
+  }
+
+  if (aOptions.mAttributeOldValue.WasPassed() &&
+      aOptions.mAttributeOldValue.Value() &&
+      aOptions.mAttributes.WasPassed() &&
+      !aOptions.mAttributes.Value()) {
+    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
+    return;
+  }
+
+  if (aOptions.mAttributeFilter.WasPassed() &&
+      aOptions.mAttributes.WasPassed() &&
+      !aOptions.mAttributes.Value()) {
+    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
+    return;
+  }
+
+  if (aOptions.mCharacterDataOldValue.WasPassed() &&
+      aOptions.mCharacterDataOldValue.Value() &&
+      aOptions.mCharacterData.WasPassed() &&
+      !aOptions.mCharacterData.Value()) {
+    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
+    return;
+  }
+
+  nsCOMArray<nsIAtom> filters;
+  bool allAttrs = true;
+  if (aOptions.mAttributeFilter.WasPassed()) {
+    allAttrs = false;
+    const mozilla::dom::Sequence<nsString>& filtersAsString =
+      aOptions.mAttributeFilter.Value();
+    uint32_t len = filtersAsString.Length();
+    filters.SetCapacity(len);
+
+    for (uint32_t i = 0; i < len; ++i) {
+      filters.AppendElement(NS_Atomize(filtersAsString[i]));
+    }
+  }
+
+  nsMutationReceiver* r = GetReceiverFor(&aTarget, true, animations);
+  r->SetChildList(childList);
+  r->SetAttributes(attributes);
+  r->SetCharacterData(characterData);
+  r->SetSubtree(subtree);
+  r->SetAttributeOldValue(attributeOldValue);
+  r->SetCharacterDataOldValue(characterDataOldValue);
+  r->SetNativeAnonymousChildList(nativeAnonymousChildList);
+  r->SetAttributeFilter(Move(filters));
+  r->SetAllAttributes(allAttrs);
+  r->SetAnimations(animations);
+  r->RemoveClones();
+
+#ifdef DEBUG
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    NS_WARNING_ASSERTION(mReceivers[i]->Target(),
+                         "All the receivers should have a target!");
+  }
+#endif
+}
+
+void
+nsDOMMutationObserver::Disconnect()
+{
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    mReceivers[i]->Disconnect(false);
+  }
+  mReceivers.Clear();
+  mCurrentMutations.Clear();
+  ClearPendingRecords();
+}
+
+void
+nsDOMMutationObserver::TakeRecords(
+                         nsTArray<RefPtr<nsDOMMutationRecord> >& aRetVal)
+{
+  aRetVal.Clear();
+  aRetVal.SetCapacity(mPendingMutationCount);
+  RefPtr<nsDOMMutationRecord> current;
+  current.swap(mFirstPendingMutation);
+  for (uint32_t i = 0; i < mPendingMutationCount; ++i) {
+    RefPtr<nsDOMMutationRecord> next;
+    current->mNext.swap(next);
+    if (!mMergeAttributeRecords ||
+        !MergeableAttributeRecord(aRetVal.SafeLastElement(nullptr),
+                                  current)) {
+      *aRetVal.AppendElement() = current.forget();
+    }
+    current.swap(next);
+  }
+  ClearPendingRecords();
+}
+
+void
+nsDOMMutationObserver::GetObservingInfo(
+                         nsTArray<Nullable<MutationObservingInfo>>& aResult,
+                         mozilla::ErrorResult& aRv)
+{
+  aResult.SetCapacity(mReceivers.Count());
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    MutationObservingInfo& info = aResult.AppendElement()->SetValue();
+    nsMutationReceiver* mr = mReceivers[i];
+    info.mChildList = mr->ChildList();
+    info.mAttributes.Construct(mr->Attributes());
+    info.mCharacterData.Construct(mr->CharacterData());
+    info.mSubtree = mr->Subtree();
+    info.mAttributeOldValue.Construct(mr->AttributeOldValue());
+    info.mCharacterDataOldValue.Construct(mr->CharacterDataOldValue());
+    info.mNativeAnonymousChildList = mr->NativeAnonymousChildList();
+    info.mAnimations = mr->Animations();
+    nsCOMArray<nsIAtom>& filters = mr->AttributeFilter();
+    if (filters.Count()) {
+      info.mAttributeFilter.Construct();
+      mozilla::dom::Sequence<nsString>& filtersAsStrings =
+        info.mAttributeFilter.Value();
+      nsString* strings = filtersAsStrings.AppendElements(filters.Count(),
+                                                          mozilla::fallible);
+      if (!strings) {
+        aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+        return;
+      }
+      for (int32_t j = 0; j < filters.Count(); ++j) {
+        filters[j]->ToString(strings[j]);
+      }
+    }
+    info.mObservedNode = mr->Target();
+  }
+}
+
+// static
+already_AddRefed<nsDOMMutationObserver>
+nsDOMMutationObserver::Constructor(const mozilla::dom::GlobalObject& aGlobal,
+                                   mozilla::dom::MutationCallback& aCb,
+                                   mozilla::ErrorResult& aRv)
+{
+  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aGlobal.GetAsSupports());
+  if (!window) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+  MOZ_ASSERT(window->IsInnerWindow());
+  bool isChrome = nsContentUtils::IsChromeDoc(window->GetExtantDoc());
+  RefPtr<nsDOMMutationObserver> observer =
+    new nsDOMMutationObserver(window.forget(), aCb, isChrome);
+  return observer.forget();
+}
+
+
+bool
+nsDOMMutationObserver::MergeableAttributeRecord(nsDOMMutationRecord* aOldRecord,
+                                                nsDOMMutationRecord* aRecord)
+{
+  MOZ_ASSERT(mMergeAttributeRecords);
+  return
+    aOldRecord &&
+    aOldRecord->mType == nsGkAtoms::attributes &&
+    aOldRecord->mType == aRecord->mType &&
+    aOldRecord->mTarget == aRecord->mTarget &&
+    aOldRecord->mAttrName == aRecord->mAttrName &&
+    aOldRecord->mAttrNamespace.Equals(aRecord->mAttrNamespace);
+}
+
+void
+nsDOMMutationObserver::HandleMutation()
+{
+  NS_ASSERTION(nsContentUtils::IsSafeToRunScript(), "Whaat!");
+  NS_ASSERTION(mCurrentMutations.IsEmpty(),
+               "Still generating MutationRecords?");
+
+  mWaitingForRun = false;
+
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    mReceivers[i]->RemoveClones();
+  }
+  mTransientReceivers.Clear();
+
+  nsPIDOMWindowOuter* outer = mOwner->GetOuterWindow();
+  if (!mPendingMutationCount || !outer ||
+      outer->GetCurrentInnerWindow() != mOwner) {
+    ClearPendingRecords();
+    return;
+  }
+
+  mozilla::dom::Sequence<mozilla::OwningNonNull<nsDOMMutationRecord> >
+    mutations;
+  if (mutations.SetCapacity(mPendingMutationCount, mozilla::fallible)) {
+    // We can't use TakeRecords easily here, because it deals with a
+    // different type of array, and we want to optimize out any extra copying.
+    RefPtr<nsDOMMutationRecord> current;
+    current.swap(mFirstPendingMutation);
+    for (uint32_t i = 0; i < mPendingMutationCount; ++i) {
+      RefPtr<nsDOMMutationRecord> next;
+      current->mNext.swap(next);
+      if (!mMergeAttributeRecords ||
+          !MergeableAttributeRecord(mutations.Length() ?
+                                      mutations.LastElement().get() : nullptr,
+                                    current)) {
+        *mutations.AppendElement(mozilla::fallible) = current;
+      }
+      current.swap(next);
+    }
+  }
+  ClearPendingRecords();
+
+  mCallback->Call(this, mutations, *this);
+}
+
+class AsyncMutationHandler : public mozilla::Runnable
+{
+public:
+  NS_IMETHOD Run() override
+  {
+    nsDOMMutationObserver::HandleMutations();
+    return NS_OK;
+  }
+};
+
+void
+nsDOMMutationObserver::HandleMutationsInternal()
+{
+  if (!nsContentUtils::IsSafeToRunScript()) {
+    nsContentUtils::AddScriptRunner(new AsyncMutationHandler());
+    return;
+  }
+  static RefPtr<nsDOMMutationObserver> sCurrentObserver;
+  if (sCurrentObserver && !sCurrentObserver->Suppressed()) {
+    // In normal cases sScheduledMutationObservers will be handled
+    // after previous mutations are handled. But in case some
+    // callback calls a sync API, which spins the eventloop, we need to still
+    // process other mutations happening during that sync call.
+    // This does *not* catch all cases, but should work for stuff running
+    // in separate tabs.
+    return;
+  }
+
+  mozilla::AutoSlowOperation aso;
+
+  nsTArray<RefPtr<nsDOMMutationObserver> >* suppressedObservers = nullptr;
+
+  while (sScheduledMutationObservers) {
+    AutoTArray<RefPtr<nsDOMMutationObserver>, 4>* observers =
+      sScheduledMutationObservers;
+    sScheduledMutationObservers = nullptr;
+    for (uint32_t i = 0; i < observers->Length(); ++i) {
+      sCurrentObserver = static_cast<nsDOMMutationObserver*>((*observers)[i]);
+      if (!sCurrentObserver->Suppressed()) {
+        sCurrentObserver->HandleMutation();
+      } else {
+        if (!suppressedObservers) {
+          suppressedObservers = new nsTArray<RefPtr<nsDOMMutationObserver> >;
+        }
+        if (!suppressedObservers->Contains(sCurrentObserver)) {
+          suppressedObservers->AppendElement(sCurrentObserver);
+        }
+      }
+    }
+    delete observers;
+    aso.CheckForInterrupt();
+  }
+
+  if (suppressedObservers) {
+    for (uint32_t i = 0; i < suppressedObservers->Length(); ++i) {
+      static_cast<nsDOMMutationObserver*>(suppressedObservers->ElementAt(i))->
+        RescheduleForRun();
+    }
+    delete suppressedObservers;
+    suppressedObservers = nullptr;
+  }
+  sCurrentObserver = nullptr;
+}
+
+nsDOMMutationRecord*
+nsDOMMutationObserver::CurrentRecord(nsIAtom* aType)
+{
+  NS_ASSERTION(sMutationLevel > 0, "Unexpected mutation level!");
+
+  while (mCurrentMutations.Length() < sMutationLevel) {
+    mCurrentMutations.AppendElement(static_cast<nsDOMMutationRecord*>(nullptr));
+  }
+
+  uint32_t last = sMutationLevel - 1;
+  if (!mCurrentMutations[last]) {
+    RefPtr<nsDOMMutationRecord> r = new nsDOMMutationRecord(aType, GetParentObject());
+    mCurrentMutations[last] = r;
+    AppendMutationRecord(r.forget());
+    ScheduleForRun();
+  }
+
+#ifdef DEBUG
+  MOZ_ASSERT(sCurrentlyHandlingObservers->Length() == sMutationLevel);
+  for (size_t i = 0; i < sCurrentlyHandlingObservers->Length(); ++i) {
+    MOZ_ASSERT(sCurrentlyHandlingObservers->ElementAt(i).Contains(this),
+               "MutationObserver should be added as an observer of all the "
+               "nested mutations!");
+  }
+#endif
+
+  NS_ASSERTION(mCurrentMutations[last]->mType == aType,
+               "Unexpected MutationRecord type!");
+
+  return mCurrentMutations[last];
+}
+
+nsDOMMutationObserver::~nsDOMMutationObserver()
+{
+  for (int32_t i = 0; i < mReceivers.Count(); ++i) {
+    mReceivers[i]->RemoveClones();
+  }
+}
+
+void
+nsDOMMutationObserver::EnterMutationHandling()
+{
+  ++sMutationLevel;
+}
+
+// Leave the current mutation level (there can be several levels if in case
+// of nested calls to the nsIMutationObserver methods).
+// The most recent mutation record is removed from mCurrentMutations, so
+// that is doesn't get modified anymore by receivers.
+void
+nsDOMMutationObserver::LeaveMutationHandling()
+{
+  if (sCurrentlyHandlingObservers &&
+      sCurrentlyHandlingObservers->Length() == sMutationLevel) {
+    nsTArray<RefPtr<nsDOMMutationObserver> >& obs =
+      sCurrentlyHandlingObservers->ElementAt(sMutationLevel - 1);
+    for (uint32_t i = 0; i < obs.Length(); ++i) {
+      nsDOMMutationObserver* o =
+        static_cast<nsDOMMutationObserver*>(obs[i]);
+      if (o->mCurrentMutations.Length() == sMutationLevel) {
+        // It is already in pending mutations.
+        o->mCurrentMutations.RemoveElementAt(sMutationLevel - 1);
+      }
+    }
+    sCurrentlyHandlingObservers->RemoveElementAt(sMutationLevel - 1);
+  }
+  --sMutationLevel;
+}
+
+void
+nsDOMMutationObserver::AddCurrentlyHandlingObserver(nsDOMMutationObserver* aObserver,
+                                                    uint32_t aMutationLevel)
+{
+  NS_ASSERTION(aMutationLevel > 0, "Unexpected mutation level!");
+
+  if (aMutationLevel > 1) {
+    // MutationObserver must be in the currently handling observer list
+    // in all the nested levels.
+    AddCurrentlyHandlingObserver(aObserver, aMutationLevel - 1);
+  }
+
+  if (!sCurrentlyHandlingObservers) {
+    sCurrentlyHandlingObservers =
+      new AutoTArray<AutoTArray<RefPtr<nsDOMMutationObserver>, 4>, 4>;
+  }
+
+  while (sCurrentlyHandlingObservers->Length() < aMutationLevel) {
+    sCurrentlyHandlingObservers->InsertElementAt(
+      sCurrentlyHandlingObservers->Length());
+  }
+
+  uint32_t index = aMutationLevel - 1;
+  if (!sCurrentlyHandlingObservers->ElementAt(index).Contains(aObserver)) {
+    sCurrentlyHandlingObservers->ElementAt(index).AppendElement(aObserver);
+  }
+}
+
+void
+nsDOMMutationObserver::Shutdown()
+{
+  delete sCurrentlyHandlingObservers;
+  sCurrentlyHandlingObservers = nullptr;
+  delete sScheduledMutationObservers;
+  sScheduledMutationObservers = nullptr;
+}
+
+nsAutoMutationBatch*
+nsAutoMutationBatch::sCurrentBatch = nullptr;
+
+void
+nsAutoMutationBatch::Done()
+{
+  if (sCurrentBatch != this) {
+    return;
+  }
+
+  sCurrentBatch = mPreviousBatch;
+  if (mObservers.IsEmpty()) {
+    nsDOMMutationObserver::LeaveMutationHandling();
+    // Nothing to do.
+    return;
+  }
+
+  uint32_t len = mObservers.Length();
+  for (uint32_t i = 0; i < len; ++i) {
+    nsDOMMutationObserver* ob = mObservers[i].mObserver;
+    bool wantsChildList = mObservers[i].mWantsChildList;
+
+    RefPtr<nsSimpleContentList> removedList;
+    if (wantsChildList) {
+      removedList = new nsSimpleContentList(mBatchTarget);
+    }
+
+    nsTArray<nsMutationReceiver*> allObservers;
+    ob->GetAllSubtreeObserversFor(mBatchTarget, allObservers);
+
+    int32_t j = mFromFirstToLast ? 0 : mRemovedNodes.Length() - 1;
+    int32_t end = mFromFirstToLast ? mRemovedNodes.Length() : -1;
+    for (; j != end; mFromFirstToLast ? ++j : --j) {
+      nsCOMPtr<nsIContent> removed = mRemovedNodes[j];
+      if (removedList) {
+        removedList->AppendElement(removed);
+      }
+
+      if (allObservers.Length()) {
+        nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
+        ob->mTransientReceivers.Get(removed, &transientReceivers);
+        if (!transientReceivers) {
+          transientReceivers = new nsCOMArray<nsMutationReceiver>();
+          ob->mTransientReceivers.Put(removed, transientReceivers);
+        }
+        for (uint32_t k = 0; k < allObservers.Length(); ++k) {
+          nsMutationReceiver* r = allObservers[k];
+          nsMutationReceiver* orig = r->GetParent() ? r->GetParent() : r;
+          if (ob->GetReceiverFor(removed, false, false) != orig) {
+            // Make sure the elements which are removed from the
+            // subtree are kept in the same observation set.
+            nsMutationReceiver* tr;
+            if (orig->Animations()) {
+              tr = nsAnimationReceiver::Create(removed, orig);
+            } else {
+              tr = nsMutationReceiver::Create(removed, orig);
+            }
+            transientReceivers->AppendObject(tr);
+          }
+        }
+      }
+    }
+    if (wantsChildList && (mRemovedNodes.Length() || mAddedNodes.Length())) {
+      RefPtr<nsSimpleContentList> addedList =
+        new nsSimpleContentList(mBatchTarget);
+      for (uint32_t i = 0; i < mAddedNodes.Length(); ++i) {
+        addedList->AppendElement(mAddedNodes[i]);
+      }
+      RefPtr<nsDOMMutationRecord> m =
+        new nsDOMMutationRecord(nsGkAtoms::childList,
+                                ob->GetParentObject());
+      m->mTarget = mBatchTarget;
+      m->mRemovedNodes = removedList;
+      m->mAddedNodes = addedList;
+      m->mPreviousSibling = mPrevSibling;
+      m->mNextSibling = mNextSibling;
+      ob->AppendMutationRecord(m.forget());
+    }
+    // Always schedule the observer so that transient receivers are
+    // removed correctly.
+    ob->ScheduleForRun();
+  }
+  nsDOMMutationObserver::LeaveMutationHandling();
+}
+
+nsAutoAnimationMutationBatch*
+nsAutoAnimationMutationBatch::sCurrentBatch = nullptr;
+
+void
+nsAutoAnimationMutationBatch::Done()
+{
+  if (sCurrentBatch != this) {
+    return;
+  }
+
+  sCurrentBatch = nullptr;
+  if (mObservers.IsEmpty()) {
+    nsDOMMutationObserver::LeaveMutationHandling();
+    // Nothing to do.
+    return;
+  }
+
+  mBatchTargets.Sort(TreeOrderComparator());
+
+  for (nsDOMMutationObserver* ob : mObservers) {
+    bool didAddRecords = false;
+
+    for (nsINode* target : mBatchTargets) {
+      EntryArray* entries = mEntryTable.Get(target);
+      MOZ_ASSERT(entries,
+        "Targets in entry table and targets list should match");
+
+      RefPtr<nsDOMMutationRecord> m =
+        new nsDOMMutationRecord(nsGkAtoms::animations, ob->GetParentObject());
+      m->mTarget = target;
+
+      for (const Entry& e : *entries) {
+        if (e.mState == eState_Added) {
+          m->mAddedAnimations.AppendElement(e.mAnimation);
+        } else if (e.mState == eState_Removed) {
+          m->mRemovedAnimations.AppendElement(e.mAnimation);
+        } else if (e.mState == eState_RemainedPresent && e.mChanged) {
+          m->mChangedAnimations.AppendElement(e.mAnimation);
+        }
+      }
+
+      if (!m->mAddedAnimations.IsEmpty() ||
+          !m->mChangedAnimations.IsEmpty() ||
+          !m->mRemovedAnimations.IsEmpty()) {
+        ob->AppendMutationRecord(m.forget());
+        didAddRecords = true;
+      }
+    }
+
+    if (didAddRecords) {
+      ob->ScheduleForRun();
+    }
+  }
+  nsDOMMutationObserver::LeaveMutationHandling();
+}