diff -r 000000000000 -r 6474c204b198 content/base/src/ShadowRoot.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/base/src/ShadowRoot.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,705 @@
+/* -*- 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/. */
+
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/ShadowRoot.h"
+#include "mozilla/dom/ShadowRootBinding.h"
+#include "mozilla/dom/DocumentFragment.h"
+#include "ChildIterator.h"
+#include "nsContentUtils.h"
+#include "nsDOMClassInfoID.h"
+#include "nsIDOMHTMLElement.h"
+#include "nsIStyleSheetLinkingElement.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLContentElement.h"
+#include "mozilla/dom/HTMLShadowElement.h"
+#include "nsXBLPrototypeBinding.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+static PLDHashOperator
+IdentifierMapEntryTraverse(nsIdentifierMapEntry *aEntry, void *aArg)
+{
+  nsCycleCollectionTraversalCallback *cb =
+    static_cast<nsCycleCollectionTraversalCallback*>(aArg);
+  aEntry->Traverse(cb);
+  return PL_DHASH_NEXT;
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(ShadowRoot)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(ShadowRoot,
+                                                  DocumentFragment)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPoolHost)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheetList)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOlderShadow)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mYoungerShadow)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAssociatedBinding)
+  tmp->mIdentifierMap.EnumerateEntries(IdentifierMapEntryTraverse, &cb);
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(ShadowRoot,
+                                                DocumentFragment)
+  if (tmp->mPoolHost) {
+    tmp->mPoolHost->RemoveMutationObserver(tmp);
+  }
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPoolHost)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mStyleSheetList)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOlderShadow)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mYoungerShadow)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mAssociatedBinding)
+  tmp->mIdentifierMap.Clear();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+DOMCI_DATA(ShadowRoot, ShadowRoot)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ShadowRoot)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContent)
+  NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
+NS_INTERFACE_MAP_END_INHERITING(DocumentFragment)
+
+NS_IMPL_ADDREF_INHERITED(ShadowRoot, DocumentFragment)
+NS_IMPL_RELEASE_INHERITED(ShadowRoot, DocumentFragment)
+
+ShadowRoot::ShadowRoot(nsIContent* aContent,
+                       already_AddRefed<nsINodeInfo>&& aNodeInfo,
+                       nsXBLPrototypeBinding* aProtoBinding)
+  : DocumentFragment(aNodeInfo), mPoolHost(aContent),
+    mProtoBinding(aProtoBinding), mShadowElement(nullptr),
+    mInsertionPointChanged(false)
+{
+  SetHost(aContent);
+  SetFlags(NODE_IS_IN_SHADOW_TREE);
+  // ShadowRoot isn't really in the document but it behaves like it is.
+  SetInDocument();
+  DOMSlots()->mBindingParent = aContent;
+  DOMSlots()->mContainingShadow = this;
+
+  // Add the ShadowRoot as a mutation observer on the host to watch
+  // for mutations because the insertion points in this ShadowRoot
+  // may need to be updated when the host children are modified.
+  mPoolHost->AddMutationObserver(this);
+}
+
+ShadowRoot::~ShadowRoot()
+{
+  if (mPoolHost) {
+    // mPoolHost may have been unlinked or a new ShadowRoot may have been
+    // creating, making this one obsolete.
+    mPoolHost->RemoveMutationObserver(this);
+  }
+
+  ClearInDocument();
+  SetHost(nullptr);
+}
+
+JSObject*
+ShadowRoot::WrapObject(JSContext* aCx)
+{
+  return mozilla::dom::ShadowRootBinding::Wrap(aCx, this);
+}
+
+ShadowRoot*
+ShadowRoot::FromNode(nsINode* aNode)
+{
+  if (aNode->HasFlag(NODE_IS_IN_SHADOW_TREE) && !aNode->GetParentNode()) {
+    MOZ_ASSERT(aNode->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE,
+               "ShadowRoot is a document fragment.");
+    return static_cast<ShadowRoot*>(aNode);
+  }
+
+  return nullptr;
+}
+
+void
+ShadowRoot::Restyle()
+{
+  mProtoBinding->FlushSkinSheets();
+
+  nsIPresShell* shell = OwnerDoc()->GetShell();
+  if (shell) {
+    OwnerDoc()->BeginUpdate(UPDATE_STYLE);
+    shell->RestyleShadowRoot(this);
+    OwnerDoc()->EndUpdate(UPDATE_STYLE);
+  }
+}
+
+void
+ShadowRoot::InsertSheet(nsCSSStyleSheet* aSheet,
+                        nsIContent* aLinkingContent)
+{
+  nsCOMPtr<nsIStyleSheetLinkingElement>
+    linkingElement = do_QueryInterface(aLinkingContent);
+  MOZ_ASSERT(linkingElement, "The only styles in a ShadowRoot should come "
+                             "from <style>.");
+
+  linkingElement->SetStyleSheet(aSheet); // This sets the ownerNode on the sheet
+
+  nsTArray<nsRefPtr<nsCSSStyleSheet> >* sheets =
+    mProtoBinding->GetOrCreateStyleSheets();
+  MOZ_ASSERT(sheets, "Style sheets array should never be null.");
+
+  // Find the correct position to insert into the style sheet list (must
+  // be in tree order).
+  for (uint32_t i = 0; i <= sheets->Length(); i++) {
+    if (i == sheets->Length()) {
+      sheets->AppendElement(aSheet);
+      break;
+    }
+
+    nsINode* sheetOwnerNode = sheets->ElementAt(i)->GetOwnerNode();
+    if (nsContentUtils::PositionIsBefore(aLinkingContent, sheetOwnerNode)) {
+      sheets->InsertElementAt(i, aSheet);
+      break;
+    }
+  }
+
+  Restyle();
+}
+
+void
+ShadowRoot::RemoveSheet(nsCSSStyleSheet* aSheet)
+{
+  nsTArray<nsRefPtr<nsCSSStyleSheet> >* sheets =
+    mProtoBinding->GetOrCreateStyleSheets();
+  MOZ_ASSERT(sheets, "Style sheets array should never be null.");
+
+  DebugOnly<bool> found = sheets->RemoveElement(aSheet);
+  MOZ_ASSERT(found, "Trying to remove a sheet from a ShadowRoot "
+                    "that does not exist.");
+
+  Restyle();
+}
+
+Element*
+ShadowRoot::GetElementById(const nsAString& aElementId)
+{
+  nsIdentifierMapEntry *entry = mIdentifierMap.GetEntry(aElementId);
+  return entry ? entry->GetIdElement() : nullptr;
+}
+
+already_AddRefed<nsContentList>
+ShadowRoot::GetElementsByTagName(const nsAString& aTagName)
+{
+  return NS_GetContentList(this, kNameSpaceID_Unknown, aTagName);
+}
+
+already_AddRefed<nsContentList>
+ShadowRoot::GetElementsByTagNameNS(const nsAString& aNamespaceURI,
+                                   const nsAString& aLocalName)
+{
+  int32_t nameSpaceId = kNameSpaceID_Wildcard;
+
+  if (!aNamespaceURI.EqualsLiteral("*")) {
+    nsresult rv =
+      nsContentUtils::NameSpaceManager()->RegisterNameSpace(aNamespaceURI,
+                                                            nameSpaceId);
+    NS_ENSURE_SUCCESS(rv, nullptr);
+  }
+
+  NS_ASSERTION(nameSpaceId != kNameSpaceID_Unknown, "Unexpected namespace ID!");
+
+  return NS_GetContentList(this, nameSpaceId, aLocalName);
+}
+
+void
+ShadowRoot::AddToIdTable(Element* aElement, nsIAtom* aId)
+{
+  nsIdentifierMapEntry *entry =
+    mIdentifierMap.PutEntry(nsDependentAtomString(aId));
+  if (entry) {
+    entry->AddIdElement(aElement);
+  }
+}
+
+void
+ShadowRoot::RemoveFromIdTable(Element* aElement, nsIAtom* aId)
+{
+  nsIdentifierMapEntry *entry =
+    mIdentifierMap.GetEntry(nsDependentAtomString(aId));
+  if (entry) {
+    entry->RemoveIdElement(aElement);
+    if (entry->IsEmpty()) {
+      mIdentifierMap.RawRemoveEntry(entry);
+    }
+  }
+}
+
+already_AddRefed<nsContentList>
+ShadowRoot::GetElementsByClassName(const nsAString& aClasses)
+{
+  return nsContentUtils::GetElementsByClassName(this, aClasses);
+}
+
+void
+ShadowRoot::AddInsertionPoint(HTMLContentElement* aInsertionPoint)
+{
+  TreeOrderComparator comparator;
+  mInsertionPoints.InsertElementSorted(aInsertionPoint, comparator);
+}
+
+void
+ShadowRoot::RemoveInsertionPoint(HTMLContentElement* aInsertionPoint)
+{
+  mInsertionPoints.RemoveElement(aInsertionPoint);
+}
+
+void
+ShadowRoot::SetYoungerShadow(ShadowRoot* aYoungerShadow)
+{
+  mYoungerShadow = aYoungerShadow;
+  mYoungerShadow->mOlderShadow = this;
+
+  ChangePoolHost(mYoungerShadow->GetShadowElement());
+}
+
+void
+ShadowRoot::DistributeSingleNode(nsIContent* aContent)
+{
+  // Find the insertion point to which the content belongs.
+  HTMLContentElement* insertionPoint = nullptr;
+  for (uint32_t i = 0; i < mInsertionPoints.Length(); i++) {
+    if (mInsertionPoints[i]->Match(aContent)) {
+      if (mInsertionPoints[i]->MatchedNodes().Contains(aContent)) {
+        // Node is already matched into the insertion point. We are done.
+        return;
+      }
+
+      // Matching may cause the insertion point to drop fallback content.
+      if (mInsertionPoints[i]->MatchedNodes().IsEmpty() &&
+          static_cast<nsINode*>(mInsertionPoints[i])->GetFirstChild()) {
+        // This match will cause the insertion point to drop all fallback
+        // content and used matched nodes instead. Give up on the optimization
+        // and just distribute all nodes.
+        DistributeAllNodes();
+        return;
+      }
+      insertionPoint = mInsertionPoints[i];
+      break;
+    }
+  }
+
+  // Find the index into the insertion point.
+  if (insertionPoint) {
+    nsCOMArray<nsIContent>& matchedNodes = insertionPoint->MatchedNodes();
+    // Find the appropriate position in the matched node list for the
+    // newly distributed content.
+    bool isIndexFound = false;
+    MOZ_ASSERT(mPoolHost, "Where did the content come from if there is no pool host?");
+    ExplicitChildIterator childIterator(mPoolHost);
+    for (uint32_t i = 0; i < matchedNodes.Length(); i++) {
+      // Seek through the host's explicit children until the inserted content
+      // is found or when the current matched node is reached.
+      if (childIterator.Seek(aContent, matchedNodes[i])) {
+        // aContent was found before the current matched node.
+        matchedNodes.InsertElementAt(i, aContent);
+        isIndexFound = true;
+        break;
+      }
+    }
+
+    if (!isIndexFound) {
+      // We have still not found an index in the insertion point,
+      // thus it must be at the end.
+      MOZ_ASSERT(childIterator.Seek(aContent),
+                 "Trying to match a node that is not a candidate to be matched");
+      matchedNodes.AppendElement(aContent);
+    }
+
+    // Handle the case where the parent of the insertion point is a ShadowRoot
+    // that is projected into the younger ShadowRoot's shadow insertion point.
+    // The node distributed into the insertion point must be reprojected
+    // to the shadow insertion point.
+    if (insertionPoint->GetParent() == this &&
+        mYoungerShadow && mYoungerShadow->GetShadowElement()) {
+      mYoungerShadow->GetShadowElement()->DistributeSingleNode(aContent);
+    }
+
+    // Handle the case where the parent of the insertion point has a ShadowRoot.
+    // The node distributed into the insertion point must be reprojected to the
+    // insertion points of the parent's ShadowRoot.
+    ShadowRoot* parentShadow = insertionPoint->GetParent()->GetShadowRoot();
+    if (parentShadow) {
+      parentShadow->DistributeSingleNode(aContent);
+    }
+
+    // Handle the case where the parent of the insertion point is the <shadow>
+    // element. The node distributed into the insertion point must be reprojected
+    // into the older ShadowRoot's insertion points.
+    if (mShadowElement && mShadowElement == insertionPoint->GetParent()) {
+      ShadowRoot* olderShadow = mShadowElement->GetOlderShadowRoot();
+      if (olderShadow) {
+        olderShadow->DistributeSingleNode(aContent);
+      }
+    }
+  }
+}
+
+void
+ShadowRoot::RemoveDistributedNode(nsIContent* aContent)
+{
+  // Find insertion point containing the content and remove the node.
+  for (uint32_t i = 0; i < mInsertionPoints.Length(); i++) {
+    if (mInsertionPoints[i]->MatchedNodes().Contains(aContent)) {
+      // Removing the matched node may cause the insertion point to use
+      // fallback content.
+      if (mInsertionPoints[i]->MatchedNodes().Length() == 1 &&
+          static_cast<nsINode*>(mInsertionPoints[i])->GetFirstChild()) {
+        // Removing the matched node will cause fallback content to be
+        // used instead. Give up optimization and distribute all nodes.
+        DistributeAllNodes();
+        return;
+      }
+
+      mInsertionPoints[i]->MatchedNodes().RemoveElement(aContent);
+
+      // Handle the case where the parent of the insertion point is a ShadowRoot
+      // that is projected into the younger ShadowRoot's shadow insertion point.
+      // The removed node needs to be removed from the shadow insertion point.
+      if (mInsertionPoints[i]->GetParent() == this) {
+        if (mYoungerShadow && mYoungerShadow->GetShadowElement()) {
+          mYoungerShadow->GetShadowElement()->RemoveDistributedNode(aContent);
+        }
+      }
+
+      // Handle the case where the parent of the insertion point has a ShadowRoot.
+      // The removed node needs to be removed from the insertion points of the
+      // parent's ShadowRoot.
+      ShadowRoot* parentShadow = mInsertionPoints[i]->GetParent()->GetShadowRoot();
+      if (parentShadow) {
+        parentShadow->RemoveDistributedNode(aContent);
+      }
+
+      // Handle the case where the parent of the insertion point is the <shadow>
+      // element. The removed node must be removed from the older ShadowRoot's
+      // insertion points.
+      if (mShadowElement && mShadowElement == mInsertionPoints[i]->GetParent()) {
+        ShadowRoot* olderShadow = mShadowElement->GetOlderShadowRoot();
+        if (olderShadow) {
+          olderShadow->RemoveDistributedNode(aContent);
+        }
+      }
+
+      break;
+    }
+  }
+}
+
+void
+ShadowRoot::DistributeAllNodes()
+{
+  // Create node pool.
+  nsTArray<nsIContent*> nodePool;
+
+  // Make sure there is a pool host, an older shadow may not have
+  // one if the younger shadow does not have a <shadow> element.
+  if (mPoolHost) {
+    ExplicitChildIterator childIterator(mPoolHost);
+    for (nsIContent* content = childIterator.GetNextChild();
+         content;
+         content = childIterator.GetNextChild()) {
+      nodePool.AppendElement(content);
+    }
+  }
+
+  nsTArray<ShadowRoot*> shadowsToUpdate;
+
+  for (uint32_t i = 0; i < mInsertionPoints.Length(); i++) {
+    mInsertionPoints[i]->ClearMatchedNodes();
+    // Assign matching nodes from node pool.
+    for (uint32_t j = 0; j < nodePool.Length(); j++) {
+      if (mInsertionPoints[i]->Match(nodePool[j])) {
+        mInsertionPoints[i]->MatchedNodes().AppendElement(nodePool[j]);
+        nodePool[j]->SetXBLInsertionParent(mInsertionPoints[i]);
+        nodePool.RemoveElementAt(j--);
+      }
+    }
+
+    // Keep track of instances where the content insertion point is distributed
+    // (parent of insertion point has a ShadowRoot).
+    nsIContent* insertionParent = mInsertionPoints[i]->GetParent();
+    MOZ_ASSERT(insertionParent, "The only way for an insertion point to be in the"
+                                "mInsertionPoints array is to be a descendant of a"
+                                "ShadowRoot, in which case, it should have a parent");
+
+    // If the parent of the insertion point has as ShadowRoot, the nodes distributed
+    // to the insertion point must be reprojected to the insertion points of the
+    // parent's ShadowRoot.
+    ShadowRoot* parentShadow = insertionParent->GetShadowRoot();
+    if (parentShadow && !shadowsToUpdate.Contains(parentShadow)) {
+      shadowsToUpdate.AppendElement(parentShadow);
+    }
+  }
+
+  // If there is a shadow insertion point in this ShadowRoot, the children
+  // of the shadow insertion point needs to be distributed into the insertion
+  // points of the older ShadowRoot.
+  if (mShadowElement && mOlderShadow) {
+    mOlderShadow->DistributeAllNodes();
+  }
+
+  // If there is a younger ShadowRoot with a shadow insertion point,
+  // then the children of this ShadowRoot needs to be distributed to
+  // the younger ShadowRoot's shadow insertion point.
+  if (mYoungerShadow && mYoungerShadow->GetShadowElement()) {
+    mYoungerShadow->GetShadowElement()->DistributeAllNodes();
+  }
+
+  for (uint32_t i = 0; i < shadowsToUpdate.Length(); i++) {
+    shadowsToUpdate[i]->DistributeAllNodes();
+  }
+}
+
+void
+ShadowRoot::GetInnerHTML(nsAString& aInnerHTML)
+{
+  GetMarkup(false, aInnerHTML);
+}
+
+void
+ShadowRoot::SetInnerHTML(const nsAString& aInnerHTML, ErrorResult& aError)
+{
+  SetInnerHTMLInternal(aInnerHTML, aError);
+}
+
+bool
+ShadowRoot::ApplyAuthorStyles()
+{
+  return mProtoBinding->InheritsStyle();
+}
+
+void
+ShadowRoot::SetApplyAuthorStyles(bool aApplyAuthorStyles)
+{
+  mProtoBinding->SetInheritsStyle(aApplyAuthorStyles);
+
+  nsIPresShell* shell = OwnerDoc()->GetShell();
+  if (shell) {
+    OwnerDoc()->BeginUpdate(UPDATE_STYLE);
+    shell->RestyleShadowRoot(this);
+    OwnerDoc()->EndUpdate(UPDATE_STYLE);
+  }
+}
+
+StyleSheetList*
+ShadowRoot::StyleSheets()
+{
+  if (!mStyleSheetList) {
+    mStyleSheetList = new ShadowRootStyleSheetList(this);
+  }
+
+  return mStyleSheetList;
+}
+
+void
+ShadowRoot::SetShadowElement(HTMLShadowElement* aShadowElement)
+{
+  // If there is already a shadow element point, remove
+  // the projected shadow because it is no longer an insertion
+  // point.
+  if (mShadowElement) {
+    mShadowElement->SetProjectedShadow(nullptr);
+  }
+
+  if (mOlderShadow) {
+    // Nodes for distribution will come from the new shadow element.
+    mOlderShadow->ChangePoolHost(aShadowElement);
+  }
+
+  // Set the new shadow element to project the older ShadowRoot because
+  // it is the current shadow insertion point.
+  mShadowElement = aShadowElement;
+  if (mShadowElement) {
+    mShadowElement->SetProjectedShadow(mOlderShadow);
+  }
+}
+
+void
+ShadowRoot::ChangePoolHost(nsIContent* aNewHost)
+{
+  if (mPoolHost) {
+    mPoolHost->RemoveMutationObserver(this);
+  }
+
+  // Clear the nodes matched to content insertion points
+  // because it is no longer relevant.
+  for (uint32_t i = 0; i < mInsertionPoints.Length(); i++) {
+    mInsertionPoints[i]->ClearMatchedNodes();
+  }
+
+  mPoolHost = aNewHost;
+  if (mPoolHost) {
+    mPoolHost->AddMutationObserver(this);
+  }
+}
+
+bool
+ShadowRoot::IsShadowInsertionPoint(nsIContent* aContent)
+{
+  if (aContent && aContent->IsHTML(nsGkAtoms::shadow)) {
+    HTMLShadowElement* shadowElem = static_cast<HTMLShadowElement*>(aContent);
+    return shadowElem->IsInsertionPoint();
+  }
+  return false;
+}
+
+/**
+ * Returns whether the web components pool population algorithm
+ * on the host would contain |aContent|. This function ignores
+ * insertion points in the pool, thus should only be used to
+ * test nodes that have not yet been distributed.
+ */
+bool
+ShadowRoot::IsPooledNode(nsIContent* aContent, nsIContent* aContainer,
+                         nsIContent* aHost)
+{
+  if (nsContentUtils::IsContentInsertionPoint(aContent) ||
+      IsShadowInsertionPoint(aContent)) {
+    // Insertion points never end up in the pool.
+    return false;
+  }
+
+  if (aContainer->IsHTML(nsGkAtoms::content)) {
+    // Fallback content will end up in pool if its parent is a child of the host.
+    HTMLContentElement* content = static_cast<HTMLContentElement*>(aContainer);
+    return content->IsInsertionPoint() && content->MatchedNodes().IsEmpty() &&
+           aContainer->GetParentNode() == aHost;
+  }
+
+  if (aContainer == aHost) {
+    // Any other child nodes of the host will end up in the pool.
+    return true;
+  }
+
+  return false;
+}
+
+void
+ShadowRoot::AttributeChanged(nsIDocument* aDocument,
+                             Element* aElement,
+                             int32_t aNameSpaceID,
+                             nsIAtom* aAttribute,
+                             int32_t aModType)
+{
+  if (!IsPooledNode(aElement, aElement->GetParent(), mPoolHost)) {
+    return;
+  }
+
+  // Attributes may change insertion point matching, find its new distribution.
+  RemoveDistributedNode(aElement);
+  DistributeSingleNode(aElement);
+}
+
+void
+ShadowRoot::ContentAppended(nsIDocument* aDocument,
+                            nsIContent* aContainer,
+                            nsIContent* aFirstNewContent,
+                            int32_t aNewIndexInContainer)
+{
+  if (mInsertionPointChanged) {
+    DistributeAllNodes();
+    mInsertionPointChanged = false;
+    return;
+  }
+
+  // Watch for new nodes added to the pool because the node
+  // may need to be added to an insertion point.
+  nsIContent* currentChild = aFirstNewContent;
+  while (currentChild) {
+    if (IsPooledNode(currentChild, aContainer, mPoolHost)) {
+      DistributeSingleNode(currentChild);
+    }
+    currentChild = currentChild->GetNextSibling();
+  }
+}
+
+void
+ShadowRoot::ContentInserted(nsIDocument* aDocument,
+                            nsIContent* aContainer,
+                            nsIContent* aChild,
+                            int32_t aIndexInContainer)
+{
+  if (mInsertionPointChanged) {
+    DistributeAllNodes();
+    mInsertionPointChanged = false;
+    return;
+  }
+
+  // Watch for new nodes added to the pool because the node
+  // may need to be added to an insertion point.
+  if (IsPooledNode(aChild, aContainer, mPoolHost)) {
+    DistributeSingleNode(aChild);
+  }
+}
+
+void
+ShadowRoot::ContentRemoved(nsIDocument* aDocument,
+                           nsIContent* aContainer,
+                           nsIContent* aChild,
+                           int32_t aIndexInContainer,
+                           nsIContent* aPreviousSibling)
+{
+  if (mInsertionPointChanged) {
+    DistributeAllNodes();
+    mInsertionPointChanged = false;
+    return;
+  }
+
+  // Watch for node that is removed from the pool because
+  // it may need to be removed from an insertion point.
+  if (IsPooledNode(aChild, aContainer, mPoolHost)) {
+    RemoveDistributedNode(aChild);
+  }
+}
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(ShadowRootStyleSheetList, StyleSheetList,
+                                   mShadowRoot)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ShadowRootStyleSheetList)
+NS_INTERFACE_MAP_END_INHERITING(StyleSheetList)
+
+NS_IMPL_ADDREF_INHERITED(ShadowRootStyleSheetList, StyleSheetList)
+NS_IMPL_RELEASE_INHERITED(ShadowRootStyleSheetList, StyleSheetList)
+
+ShadowRootStyleSheetList::ShadowRootStyleSheetList(ShadowRoot* aShadowRoot)
+  : mShadowRoot(aShadowRoot)
+{
+  MOZ_COUNT_CTOR(ShadowRootStyleSheetList);
+}
+
+ShadowRootStyleSheetList::~ShadowRootStyleSheetList()
+{
+  MOZ_COUNT_DTOR(ShadowRootStyleSheetList);
+}
+
+nsCSSStyleSheet*
+ShadowRootStyleSheetList::IndexedGetter(uint32_t aIndex, bool& aFound)
+{
+  nsTArray<nsRefPtr<nsCSSStyleSheet>>* sheets =
+    mShadowRoot->mProtoBinding->GetStyleSheets();
+
+  if (!sheets) {
+    aFound = false;
+    return nullptr;
+  }
+
+  aFound = aIndex < sheets->Length();
+  return sheets->SafeElementAt(aIndex);
+}
+
+uint32_t
+ShadowRootStyleSheetList::Length()
+{
+  nsTArray<nsRefPtr<nsCSSStyleSheet> >* sheets =
+    mShadowRoot->mProtoBinding->GetStyleSheets();
+
+  if (!sheets) {
+    return 0;
+  }
+
+  return sheets->Length();
+}
+