Bug 708901 - Migrate to nsTHashSet in dom/base. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D108593

dom/base/CustomElementRegistry.cpp

@@ -325,13 +325,13 @@ CustomElementRegistry::RunCustomElementCreationCallback::Run() {
   MOZ_ASSERT(!mRegistry->mElementCreationCallbacks.GetWeak(mAtom),
              "Callback should be removed.");
 
-  mozilla::UniquePtr<nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>> elements;
+  mozilla::UniquePtr<nsTHashSet<RefPtr<nsIWeakReference>>> elements;
   mRegistry->mElementCreationCallbacksUpgradeCandidatesMap.Remove(mAtom,
                                                                   &elements);
   MOZ_ASSERT(elements, "There should be a list");
 
-  for (auto iter = elements->ConstIter(); !iter.Done(); iter.Next()) {
+  for (const auto& key : *elements) {
-    nsCOMPtr<Element> elem = do_QueryReferent(iter.Get()->GetKey());
+    nsCOMPtr<Element> elem = do_QueryReferent(key);
     if (!elem) {
       continue;
     }
@@ -409,10 +409,10 @@ void CustomElementRegistry::RegisterUnresolvedElement(Element* aElement,
     return;
   }
 
-  nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>* unresolved =
+  nsTHashSet<RefPtr<nsIWeakReference>>* unresolved =
       mCandidatesMap.GetOrInsertNew(typeName);
   nsWeakPtr elem = do_GetWeakReference(aElement);
-  unresolved->PutEntry(elem);
+  unresolved->Insert(elem);
 }
 
 void CustomElementRegistry::UnregisterUnresolvedElement(Element* aElement,
@@ -431,10 +431,10 @@ void CustomElementRegistry::UnregisterUnresolvedElement(Element* aElement,
   }
 #endif
 
-  nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>* candidates = nullptr;
+  nsTHashSet<RefPtr<nsIWeakReference>>* candidates = nullptr;
   if (mCandidatesMap.Get(aTypeName, &candidates)) {
     MOZ_ASSERT(candidates);
-    candidates->RemoveEntry(weak);
+    candidates->Remove(weak);
   }
 }
 
@@ -549,7 +549,7 @@ namespace {
 
 class CandidateFinder {
  public:
-  CandidateFinder(nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>& aCandidates,
+  CandidateFinder(nsTHashSet<RefPtr<nsIWeakReference>>& aCandidates,
                   Document* aDoc);
   nsTArray<nsCOMPtr<Element>> OrderedCandidates();
 
@@ -559,12 +559,11 @@ class CandidateFinder {
 };
 
 CandidateFinder::CandidateFinder(
-    nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>& aCandidates,
+    nsTHashSet<RefPtr<nsIWeakReference>>& aCandidates, Document* aDoc)
-    Document* aDoc)
     : mDoc(aDoc), mCandidates(aCandidates.Count()) {
   MOZ_ASSERT(mDoc);
-  for (auto iter = aCandidates.ConstIter(); !iter.Done(); iter.Next()) {
+  for (const auto& candidate : aCandidates) {
-    nsCOMPtr<Element> elem = do_QueryReferent(iter.Get()->GetKey());
+    nsCOMPtr<Element> elem = do_QueryReferent(candidate);
     if (!elem) {
       continue;
     }
@@ -613,8 +612,7 @@ void CustomElementRegistry::UpgradeCandidates(
     return;
   }
 
-  mozilla::UniquePtr<nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>>
+  mozilla::UniquePtr<nsTHashSet<RefPtr<nsIWeakReference>>> candidates;
-      candidates;
   if (mCandidatesMap.Remove(aKey, &candidates)) {
     MOZ_ASSERT(candidates);
     CustomElementReactionsStack* reactionsStack =

dom/base/CustomElementRegistry.h

@@ -20,6 +20,7 @@
 #include "nsGenericHTMLElement.h"
 #include "nsWrapperCache.h"
 #include "nsContentUtils.h"
+#include "nsTHashSet.h"
 
 namespace mozilla {
 class ErrorResult;
@@ -474,7 +475,7 @@ class CustomElementRegistry final : public nsISupports, public nsWrapperCache {
       typeName = aElement->NodeInfo()->NameAtom();
     }
 
-    nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>* elements =
+    nsTHashSet<RefPtr<nsIWeakReference>>* elements =
         mElementCreationCallbacksUpgradeCandidatesMap.Get(typeName);
 
     // If there isn't a table, there won't be a definition added by the
@@ -484,7 +485,7 @@ class CustomElementRegistry final : public nsISupports, public nsWrapperCache {
     }
 
     nsWeakPtr elem = do_GetWeakReference(aElement);
-    elements->PutEntry(elem);
+    elements->Insert(elem);
   }
 
   void TraceDefinitions(JSTracer* aTrc);
@@ -511,7 +512,7 @@ class CustomElementRegistry final : public nsISupports, public nsWrapperCache {
                             CustomElementCreationCallback>
       ElementCreationCallbackMap;
   typedef nsClassHashtable<nsRefPtrHashKey<nsAtom>,
-                           nsTHashtable<nsRefPtrHashKey<nsIWeakReference>>>
+                           nsTHashSet<RefPtr<nsIWeakReference>>>
       CandidateMap;
   typedef JS::GCHashMap<JS::Heap<JSObject*>, RefPtr<nsAtom>,
                         js::MovableCellHasher<JS::Heap<JSObject*>>,

dom/base/DocGroup.cpp

@@ -377,7 +377,7 @@ nsresult DocGroup::QueueIframePostMessages(
     MOZ_ASSERT(mIframePostMessageQueue);
     MOZ_ASSERT(mIframePostMessageQueue->IsPaused());
 
-    mIframesUsedPostMessageQueue.PutEntry(aWindowId);
+    mIframesUsedPostMessageQueue.Insert(aWindowId);
 
     mIframePostMessageQueue->Dispatch(std::move(aRunnable), NS_DISPATCH_NORMAL);
     return NS_OK;
@@ -387,7 +387,7 @@ nsresult DocGroup::QueueIframePostMessages(
 
 void DocGroup::TryFlushIframePostMessages(uint64_t aWindowId) {
   if (DocGroup::TryToLoadIframesInBackground()) {
-    mIframesUsedPostMessageQueue.RemoveEntry(aWindowId);
+    mIframesUsedPostMessageQueue.Remove(aWindowId);
     if (mIframePostMessageQueue && mIframesUsedPostMessageQueue.IsEmpty()) {
       MOZ_ASSERT(mIframePostMessageQueue->IsPaused());
       nsresult rv = mIframePostMessageQueue->SetIsPaused(true);

dom/base/DocGroup.h

@@ -10,7 +10,7 @@
 #include "nsISupportsImpl.h"
 #include "nsIPrincipal.h"
 #include "nsThreadUtils.h"
-#include "nsTHashtable.h"
+#include "nsTHashSet.h"
 #include "nsString.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/dom/BrowsingContextGroup.h"
@@ -141,7 +141,7 @@ class DocGroup final {
   RefPtr<mozilla::PerformanceCounter> mPerformanceCounter;
   RefPtr<BrowsingContextGroup> mBrowsingContextGroup;
   RefPtr<mozilla::ThrottledEventQueue> mIframePostMessageQueue;
-  nsTHashtable<nsUint64HashKey> mIframesUsedPostMessageQueue;
+  nsTHashSet<uint64_t> mIframesUsedPostMessageQueue;
   nsCOMPtr<nsISerialEventTarget> mEventTarget;
 
   // non-null if the JS execution for this docgroup is regulated with regards

dom/base/Document.cpp

@@ -4090,7 +4090,7 @@ AbstractThread* Document::AbstractMainThreadFor(
 void Document::NoteScriptTrackingStatus(const nsACString& aURL,
                                         bool aIsTracking) {
   if (aIsTracking) {
-    mTrackingScripts.PutEntry(aURL);
+    mTrackingScripts.Insert(aURL);
   } else {
     MOZ_ASSERT(!mTrackingScripts.Contains(aURL));
   }
@@ -8334,9 +8334,7 @@ already_AddRefed<Attr> Document::CreateAttributeNS(
 }
 
 void Document::ResolveScheduledSVGPresAttrs() {
-  for (auto iter = mLazySVGPresElements.ConstIter(); !iter.Done();
+  for (SVGElement* svg : mLazySVGPresElements) {
-       iter.Next()) {
-    SVGElement* svg = iter.Get()->GetKey();
     svg->UpdateContentDeclarationBlock();
   }
   mLazySVGPresElements.Clear();
@@ -11618,10 +11616,7 @@ void Document::RefreshLinkHrefs() {
   // Get a list of all links we know about.  We will reset them, which will
   // remove them from the document, so we need a copy of what is in the
   // hashtable.
-  LinkArray linksToNotify(mStyledLinks.Count());
+  const LinkArray linksToNotify = ToArray(mStyledLinks);
-  for (auto iter = mStyledLinks.ConstIter(); !iter.Done(); iter.Next()) {
-    linksToNotify.AppendElement(iter.Get()->GetKey());
-  }
 
   // Reset all of our styled links.
   nsAutoScriptBlocker scriptBlocker;
@@ -12563,21 +12558,16 @@ void Document::ScrollToRef() {
 
 void Document::RegisterActivityObserver(nsISupports* aSupports) {
   if (!mActivityObservers) {
-    mActivityObservers = MakeUnique<nsTHashtable<nsPtrHashKey<nsISupports>>>();
+    mActivityObservers = MakeUnique<nsTHashSet<nsISupports*>>();
   }
-  mActivityObservers->PutEntry(aSupports);
+  mActivityObservers->Insert(aSupports);
 }
 
 bool Document::UnregisterActivityObserver(nsISupports* aSupports) {
   if (!mActivityObservers) {
     return false;
   }
-  nsPtrHashKey<nsISupports>* entry = mActivityObservers->GetEntry(aSupports);
+  return mActivityObservers->EnsureRemoved(aSupports);
-  if (!entry) {
-    return false;
-  }
-  mActivityObservers->RemoveEntry(entry);
-  return true;
 }
 
 void Document::EnumerateActivityObservers(
@@ -12586,12 +12576,9 @@ void Document::EnumerateActivityObservers(
     return;
   }
 
-  nsTArray<nsCOMPtr<nsISupports>> observers(mActivityObservers->Count());
+  const auto keyArray =
-  for (auto iter = mActivityObservers->ConstIter(); !iter.Done(); iter.Next()) {
+      ToTArray<nsTArray<nsCOMPtr<nsISupports>>>(*mActivityObservers);
-    observers.AppendElement(iter.Get()->GetKey());
+  for (auto& observer : keyArray) {
-  }
-
-  for (auto& observer : observers) {
     aEnumerator(observer.get());
   }
 }
@@ -13032,10 +13019,7 @@ mozilla::dom::ImageTracker* Document::ImageTracker() {
 }
 
 void Document::GetPlugins(nsTArray<nsIObjectLoadingContent*>& aPlugins) {
-  aPlugins.SetCapacity(aPlugins.Length() + mPlugins.Count());
+  aPlugins.AppendElements(ToArray(mPlugins));
-  for (auto iter = mPlugins.ConstIter(); !iter.Done(); iter.Next()) {
-    aPlugins.AppendElement(iter.Get()->GetKey());
-  }
   auto recurse = [&aPlugins](Document& aSubDoc) {
     aSubDoc.GetPlugins(aPlugins);
     return CallState::Continue;
@@ -13052,7 +13036,7 @@ void Document::ScheduleSVGUseElementShadowTreeUpdate(
     return;
   }
 
-  mSVGUseElementsNeedingShadowTreeUpdate.PutEntry(&aUseElement);
+  mSVGUseElementsNeedingShadowTreeUpdate.Insert(&aUseElement);
 
   if (PresShell* presShell = GetPresShell()) {
     presShell->EnsureStyleFlush();
@@ -13061,22 +13045,13 @@ void Document::ScheduleSVGUseElementShadowTreeUpdate(
 
 void Document::DoUpdateSVGUseElementShadowTrees() {
   MOZ_ASSERT(!mSVGUseElementsNeedingShadowTreeUpdate.IsEmpty());
-  nsTArray<RefPtr<SVGUseElement>> useElementsToUpdate;
 
   do {
-    useElementsToUpdate.Clear();
+    const auto useElementsToUpdate = ToTArray<nsTArray<RefPtr<SVGUseElement>>>(
-    useElementsToUpdate.SetCapacity(
+        mSVGUseElementsNeedingShadowTreeUpdate);
-        mSVGUseElementsNeedingShadowTreeUpdate.Count());
-
-    {
-      for (auto iter = mSVGUseElementsNeedingShadowTreeUpdate.ConstIter();
-           !iter.Done(); iter.Next()) {
-        useElementsToUpdate.AppendElement(iter.Get()->GetKey());
-      }
     mSVGUseElementsNeedingShadowTreeUpdate.Clear();
-    }
 
-    for (auto& useElement : useElementsToUpdate) {
+    for (const auto& useElement : useElementsToUpdate) {
       if (MOZ_UNLIKELY(!useElement->IsInComposedDoc())) {
         // The element was in another <use> shadow tree which we processed
         // already and also needed an update, and is removed from the document
@@ -13090,8 +13065,7 @@ void Document::DoUpdateSVGUseElementShadowTrees() {
 }
 
 void Document::NotifyMediaFeatureValuesChanged() {
-  for (auto iter = mResponsiveContent.ConstIter(); !iter.Done(); iter.Next()) {
+  for (RefPtr<HTMLImageElement> imageElement : mResponsiveContent) {
-    RefPtr<HTMLImageElement> imageElement = iter.Get()->GetKey();
     imageElement->MediaFeatureValuesChanged();
   }
 }
@@ -15469,11 +15443,8 @@ void Document::UpdateIntersectionObservations(TimeStamp aNowTime) {
     }
   }
 
-  nsTArray<RefPtr<DOMIntersectionObserver>> observers(
+  const auto observers = ToTArray<nsTArray<RefPtr<DOMIntersectionObserver>>>(
-      mIntersectionObservers.Count());
+      mIntersectionObservers);
-  for (auto& observer : mIntersectionObservers) {
-    observers.AppendElement(observer.GetKey());
-  }
   for (const auto& observer : observers) {
     if (observer) {
       observer->Update(this, time);
@@ -15493,22 +15464,12 @@ void Document::ScheduleIntersectionObserverNotification() {
 }
 
 void Document::NotifyIntersectionObservers() {
-  nsTArray<RefPtr<DOMIntersectionObserver>> observers(
+  const auto observers = ToTArray<nsTArray<RefPtr<DOMIntersectionObserver>>>(
-      mIntersectionObservers.Count());
+      mIntersectionObservers);
-  for (auto iter = mIntersectionObservers.ConstIter(); !iter.Done();
-       iter.Next()) {
-    DOMIntersectionObserver* observer = iter.Get()->GetKey();
-    observers.AppendElement(observer);
-  }
   for (const auto& observer : observers) {
     if (observer) {
-      // MOZ_KnownLive because 'observers' is guaranteed to
+      // MOZ_KnownLive because the 'observers' array guarantees to keep it
-      // keep it alive.
+      // alive.
-      //
-      // Even with https://bugzilla.mozilla.org/show_bug.cgi?id=1620312 fixed
-      // this might need to stay, because 'observers' is not const, so it's not
-      // obvious how to prove via static analysis that it won't change and
-      // release us.
       MOZ_KnownLive(observer)->Notify();
     }
   }
@@ -16985,8 +16946,8 @@ void Document::DoCacheAllKnownLangPrefs() {
   data->GetFontPrefsForLang(nsGkAtoms::x_math);
   // https://bugzilla.mozilla.org/show_bug.cgi?id=1362599#c12
   data->GetFontPrefsForLang(nsGkAtoms::Unicode);
-  for (auto iter = mLanguagesUsed.ConstIter(); !iter.Done(); iter.Next()) {
+  for (const auto& key : mLanguagesUsed) {
-    data->GetFontPrefsForLang(iter.Get()->GetKey());
+    data->GetFontPrefsForLang(key);
   }
   mMayNeedFontPrefsUpdate = false;
 }
@@ -17287,10 +17248,7 @@ bool Document::ShouldIncludeInTelemetry(bool aAllowExtensionURIs) {
 
 void Document::GetConnectedShadowRoots(
     nsTArray<RefPtr<ShadowRoot>>& aOut) const {
-  aOut.SetCapacity(mComposedShadowRoots.Count());
+  AppendToArray(aOut, mComposedShadowRoots);
-  for (const auto& entry : mComposedShadowRoots) {
-    aOut.AppendElement(entry.GetKey());
-  }
 }
 
 bool Document::HasPictureInPictureChildElement() const {

dom/base/Document.h

@@ -92,7 +92,7 @@
 #include "nsRefPtrHashtable.h"
 #include "nsString.h"
 #include "nsTArray.h"
-#include "nsTHashtable.h"
+#include "nsTHashSet.h"
 #include "nsTLiteralString.h"
 #include "nsTObserverArray.h"
 #include "nsThreadUtils.h"
@@ -1369,13 +1369,13 @@ class Document : public nsINode,
    * is removed.
    */
   void ScheduleSVGForPresAttrEvaluation(SVGElement* aSVG) {
-    mLazySVGPresElements.PutEntry(aSVG);
+    mLazySVGPresElements.Insert(aSVG);
   }
 
   // Unschedule an element scheduled by ScheduleFrameRequestCallback (e.g. for
   // when it is destroyed)
   void UnscheduleSVGForPresAttrEvaluation(SVGElement* aSVG) {
-    mLazySVGPresElements.RemoveEntry(aSVG);
+    mLazySVGPresElements.Remove(aSVG);
   }
 
   // Resolve all SVG pres attrs scheduled in ScheduleSVGForPresAttrEvaluation
@@ -2431,11 +2431,11 @@ class Document : public nsINode,
   void AddStyleRelevantLink(Link* aLink) {
     NS_ASSERTION(aLink, "Passing in a null link.  Expect crashes RSN!");
 #ifdef DEBUG
-    nsPtrHashKey<Link>* entry = mStyledLinks.GetEntry(aLink);
+    NS_ASSERTION(!mStyledLinks.Contains(aLink),
-    NS_ASSERTION(!entry, "Document already knows about this Link!");
+                 "Document already knows about this Link!");
     mStyledLinksCleared = false;
 #endif
-    mStyledLinks.PutEntry(aLink);
+    mStyledLinks.Insert(aLink);
   }
 
   /**
@@ -2447,11 +2447,11 @@ class Document : public nsINode,
   void ForgetLink(Link* aLink) {
     NS_ASSERTION(aLink, "Passing in a null link.  Expect crashes RSN!");
 #ifdef DEBUG
-    nsPtrHashKey<Link>* entry = mStyledLinks.GetEntry(aLink);
+    bool linkContained = mStyledLinks.Contains(aLink);
-    NS_ASSERTION(entry || mStyledLinksCleared,
+    NS_ASSERTION(linkContained || mStyledLinksCleared,
                  "Document knows nothing about this Link!");
 #endif
-    mStyledLinks.RemoveEntry(aLink);
+    mStyledLinks.Remove(aLink);
   }
 
   // Refreshes the hrefs of all the links in the document.
@@ -3100,14 +3100,14 @@ class Document : public nsINode,
   // added to the tree.
   void AddPlugin(nsIObjectLoadingContent* aPlugin) {
     MOZ_ASSERT(aPlugin);
-    mPlugins.PutEntry(aPlugin);
+    mPlugins.Insert(aPlugin);
   }
 
   // RemovePlugin removes a plugin-related element to mPlugins when the
   // element is removed from the tree.
   void RemovePlugin(nsIObjectLoadingContent* aPlugin) {
     MOZ_ASSERT(aPlugin);
-    mPlugins.RemoveEntry(aPlugin);
+    mPlugins.Remove(aPlugin);
   }
 
   // GetPlugins returns the plugin-related elements from
@@ -3118,33 +3118,33 @@ class Document : public nsINode,
   // added to the tree.
   void AddResponsiveContent(HTMLImageElement* aContent) {
     MOZ_ASSERT(aContent);
-    mResponsiveContent.PutEntry(aContent);
+    mResponsiveContent.Insert(aContent);
   }
 
   // Removes an element from mResponsiveContent when the element is
   // removed from the tree.
   void RemoveResponsiveContent(HTMLImageElement* aContent) {
     MOZ_ASSERT(aContent);
-    mResponsiveContent.RemoveEntry(aContent);
+    mResponsiveContent.Remove(aContent);
   }
 
   void ScheduleSVGUseElementShadowTreeUpdate(SVGUseElement&);
   void UnscheduleSVGUseElementShadowTreeUpdate(SVGUseElement& aElement) {
-    mSVGUseElementsNeedingShadowTreeUpdate.RemoveEntry(&aElement);
+    mSVGUseElementsNeedingShadowTreeUpdate.Remove(&aElement);
   }
 
   bool SVGUseElementNeedsShadowTreeUpdate(SVGUseElement& aElement) const {
-    return mSVGUseElementsNeedingShadowTreeUpdate.GetEntry(&aElement);
+    return mSVGUseElementsNeedingShadowTreeUpdate.Contains(&aElement);
   }
 
-  using ShadowRootSet = nsTHashtable<nsPtrHashKey<ShadowRoot>>;
+  using ShadowRootSet = nsTHashSet<ShadowRoot*>;
 
   void AddComposedDocShadowRoot(ShadowRoot& aShadowRoot) {
-    mComposedShadowRoots.PutEntry(&aShadowRoot);
+    mComposedShadowRoots.Insert(&aShadowRoot);
   }
 
   void RemoveComposedDocShadowRoot(ShadowRoot& aShadowRoot) {
-    mComposedShadowRoots.RemoveEntry(&aShadowRoot);
+    mComposedShadowRoots.Remove(&aShadowRoot);
   }
 
   // If you're considering using this, you probably want to use
@@ -3710,11 +3710,11 @@ class Document : public nsINode,
   void AddIntersectionObserver(DOMIntersectionObserver* aObserver) {
     MOZ_ASSERT(!mIntersectionObservers.Contains(aObserver),
                "Intersection observer already in the list");
-    mIntersectionObservers.PutEntry(aObserver);
+    mIntersectionObservers.Insert(aObserver);
   }
 
   void RemoveIntersectionObserver(DOMIntersectionObserver* aObserver) {
-    mIntersectionObservers.RemoveEntry(aObserver);
+    mIntersectionObservers.Remove(aObserver);
   }
 
   bool HasIntersectionObservers() const {
@@ -4414,7 +4414,7 @@ class Document : public nsINode,
   // See ShadowRoot::Bind and ShadowRoot::Unbind.
   ShadowRootSet mComposedShadowRoots;
 
-  using SVGUseElementSet = nsTHashtable<nsPtrHashKey<SVGUseElement>>;
+  using SVGUseElementSet = nsTHashSet<SVGUseElement*>;
 
   // The set of <svg:use> elements that need a shadow tree reclone because the
   // tree they map to has changed.
@@ -4426,10 +4426,10 @@ class Document : public nsINode,
   //
   // These are non-owning pointers, the elements are responsible for removing
   // themselves when they go away.
-  UniquePtr<nsTHashtable<nsPtrHashKey<nsISupports>>> mActivityObservers;
+  UniquePtr<nsTHashSet<nsISupports*>> mActivityObservers;
 
   // A hashtable of styled links keyed by address pointer.
-  nsTHashtable<nsPtrHashKey<Link>> mStyledLinks;
+  nsTHashSet<Link*> mStyledLinks;
 #ifdef DEBUG
   // Indicates whether mStyledLinks was cleared or not.  This is used to track
   // state so we can provide useful assertions to consumers of ForgetLink and
@@ -5029,7 +5029,7 @@ class Document : public nsINode,
   // The set of all the tracking script URLs.  URLs are added to this set by
   // calling NoteScriptTrackingStatus().  Currently we assume that a URL not
   // existing in the set means the corresponding script isn't a tracking script.
-  nsTHashtable<nsCStringHashKey> mTrackingScripts;
+  nsTHashSet<nsCString> mTrackingScripts;
 
   // Pointer to our parser if we're currently in the process of being
   // parsed into.
@@ -5095,7 +5095,7 @@ class Document : public nsINode,
   nsWeakPtr mScopeObject;
 
   // Array of intersection observers
-  nsTHashtable<nsPtrHashKey<DOMIntersectionObserver>> mIntersectionObservers;
+  nsTHashSet<DOMIntersectionObserver*> mIntersectionObservers;
 
   RefPtr<DOMIntersectionObserver> mLazyLoadImageObserver;
   // Used to measure how effective the lazyload thresholds are.
@@ -5113,10 +5113,10 @@ class Document : public nsINode,
   RefPtr<nsContentList> mImageMaps;
 
   // A set of responsive images keyed by address pointer.
-  nsTHashtable<nsPtrHashKey<HTMLImageElement>> mResponsiveContent;
+  nsTHashSet<HTMLImageElement*> mResponsiveContent;
 
   // Tracking for plugins in the document.
-  nsTHashtable<nsPtrHashKey<nsIObjectLoadingContent>> mPlugins;
+  nsTHashSet<nsIObjectLoadingContent*> mPlugins;
 
   RefPtr<DocumentTimeline> mDocumentTimeline;
   LinkedList<DocumentTimeline> mTimelines;
@@ -5182,9 +5182,9 @@ class Document : public nsINode,
   // We lazily calculate declaration blocks for SVG elements with mapped
   // attributes in Servo mode. This list contains all elements which need lazy
   // resolution.
-  nsTHashtable<nsPtrHashKey<SVGElement>> mLazySVGPresElements;
+  nsTHashSet<SVGElement*> mLazySVGPresElements;
 
-  nsTHashtable<nsRefPtrHashKey<nsAtom>> mLanguagesUsed;
+  nsTHashSet<RefPtr<nsAtom>> mLanguagesUsed;
 
   // TODO(emilio): Is this hot enough to warrant to be cached?
   RefPtr<nsAtom> mLanguageFromCharset;

dom/base/DocumentOrShadowRoot.cpp

@@ -142,7 +142,7 @@ void DocumentOrShadowRoot::SetAdoptedStyleSheets(
       break;
     }
     ++commonPrefix;
-    set.PutEntry(mAdoptedStyleSheets[i]);
+    set.Insert(mAdoptedStyleSheets[i]);
   }
 
   // Try to truncate the sheets to a common prefix.

dom/base/DocumentOrShadowRoot.h

@@ -14,6 +14,7 @@
 #include "nsClassHashtable.h"
 #include "nsContentListDeclarations.h"
 #include "nsTArray.h"
+#include "nsTHashSet.h"
 
 class nsContentList;
 class nsCycleCollectionTraversalCallback;
@@ -254,7 +255,7 @@ class DocumentOrShadowRoot {
                            nsCycleCollectionTraversalCallback&);
   void UnlinkStyleSheets(nsTArray<RefPtr<StyleSheet>>&);
 
-  using StyleSheetSet = nsTHashtable<nsPtrHashKey<const StyleSheet>>;
+  using StyleSheetSet = nsTHashSet<const StyleSheet*>;
   void RemoveSheetFromStylesIfApplicable(StyleSheet&);
   void ClearAdoptedStyleSheets();
 

dom/base/FragmentOrElement.cpp

@@ -1302,15 +1302,13 @@ nsINode* FindOptimizableSubtreeRoot(nsINode* aNode) {
   return aNode;
 }
 
-StaticAutoPtr<nsTHashtable<nsPtrHashKey<nsINode>>> gCCBlackMarkedNodes;
+StaticAutoPtr<nsTHashSet<nsINode*>> gCCBlackMarkedNodes;
 
 static void ClearBlackMarkedNodes() {
   if (!gCCBlackMarkedNodes) {
     return;
   }
-  for (auto iter = gCCBlackMarkedNodes->ConstIter(); !iter.Done();
+  for (nsINode* n : *gCCBlackMarkedNodes) {
-       iter.Next()) {
-    nsINode* n = iter.Get()->GetKey();
     n->SetCCMarkedRoot(false);
     n->SetInCCBlackTree(false);
   }
@@ -1322,7 +1320,7 @@ void FragmentOrElement::RemoveBlackMarkedNode(nsINode* aNode) {
   if (!gCCBlackMarkedNodes) {
     return;
   }
-  gCCBlackMarkedNodes->RemoveEntry(aNode);
+  gCCBlackMarkedNodes->Remove(aNode);
 }
 
 static bool IsCertainlyAliveNode(nsINode* aNode, Document* aDoc) {
@@ -1368,7 +1366,7 @@ bool FragmentOrElement::CanSkipInCC(nsINode* aNode) {
   }
 
   if (!gCCBlackMarkedNodes) {
-    gCCBlackMarkedNodes = new nsTHashtable<nsPtrHashKey<nsINode>>(1020);
+    gCCBlackMarkedNodes = new nsTHashSet<nsINode*>(1020);
   }
 
   // nodesToUnpurple contains nodes which will be removed
@@ -1412,7 +1410,7 @@ bool FragmentOrElement::CanSkipInCC(nsINode* aNode) {
 
   root->SetCCMarkedRoot(true);
   root->SetInCCBlackTree(foundLiveWrapper);
-  gCCBlackMarkedNodes->PutEntry(root);
+  gCCBlackMarkedNodes->Insert(root);
 
   if (!foundLiveWrapper) {
     return false;
@@ -1427,7 +1425,7 @@ bool FragmentOrElement::CanSkipInCC(nsINode* aNode) {
     for (uint32_t i = 0; i < grayNodes.Length(); ++i) {
       nsINode* node = grayNodes[i];
       node->SetInCCBlackTree(true);
-      gCCBlackMarkedNodes->PutEntry(node);
+      gCCBlackMarkedNodes->Insert(node);
     }
   }
 
@@ -1721,8 +1719,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(FragmentOrElement)
           static_cast<IntersectionObserverList*>(
               elem->GetProperty(nsGkAtoms::intersectionobserverlist));
       if (observers) {
-        for (const auto& entry : *observers) {
+        for (DOMIntersectionObserver* observer : observers->Keys()) {
-          DOMIntersectionObserver* observer = entry.GetKey();
           cb.NoteXPCOMChild(observer);
         }
       }

dom/base/nsDOMWindowUtils.cpp

@@ -1442,7 +1442,7 @@ nsDOMWindowUtils::GetTranslationNodes(nsINode* aRoot,
     return NS_ERROR_DOM_WRONG_DOCUMENT_ERR;
   }
 
-  nsTHashtable<nsPtrHashKey<nsIContent>> translationNodesHash(500);
+  nsTHashSet<nsIContent*> translationNodesHash(500);
   RefPtr<nsTranslationNodeList> list = new nsTranslationNodeList;
 
   uint32_t limit = 15000;
@@ -1469,7 +1469,7 @@ nsDOMWindowUtils::GetTranslationNodes(nsINode* aRoot,
     for (nsIContent* child = content->GetFirstChild(); child;
          child = child->GetNextSibling()) {
       if (child->IsText() && child->GetAsText()->HasTextForTranslation()) {
-        translationNodesHash.PutEntry(content);
+        translationNodesHash.Insert(content);
 
         nsIFrame* frame = content->GetPrimaryFrame();
         bool isTranslationRoot = frame && frame->IsBlockFrameOrSubclass();
@@ -3280,7 +3280,7 @@ nsDOMWindowUtils::IsPartOfOpaqueLayer(Element* aElement, bool* aResult) {
 NS_IMETHODIMP
 nsDOMWindowUtils::NumberOfAssignedPaintedLayers(
     const nsTArray<RefPtr<Element>>& aElements, uint32_t* aResult) {
-  nsTHashtable<nsPtrHashKey<PaintedLayer>> layers;
+  nsTHashSet<PaintedLayer*> layers;
   for (Element* element : aElements) {
     nsIFrame* frame = element->GetPrimaryFrame();
     if (!frame) {
@@ -3293,7 +3293,7 @@ nsDOMWindowUtils::NumberOfAssignedPaintedLayers(
       return NS_ERROR_FAILURE;
     }
 
-    layers.PutEntry(layer);
+    layers.Insert(layer);
   }
 
   *aResult = layers.Count();

dom/base/nsINode.cpp

@@ -322,7 +322,7 @@ bool nsINode::IsSelected(const uint32_t aStartOffset,
                "Selection is for sure not selected.");
 
   // Collect the selection objects for potential ranges.
-  nsTHashtable<nsPtrHashKey<Selection>> ancestorSelections;
+  nsTHashSet<Selection*> ancestorSelections;
   Selection* prevSelection = nullptr;
   for (; n; n = GetClosestCommonInclusiveAncestorForRangeInSelection(
                 n->GetParentNode())) {
@@ -339,7 +339,7 @@ bool nsINode::IsSelected(const uint32_t aStartOffset,
         Selection* selection = range->GetSelection();
         if (prevSelection != selection) {
           prevSelection = selection;
-          ancestorSelections.PutEntry(selection);
+          ancestorSelections.Insert(selection);
         }
       }
     }
@@ -347,8 +347,7 @@ bool nsINode::IsSelected(const uint32_t aStartOffset,
 
   nsContentUtils::ComparePointsCache cache;
   IsItemInRangeComparator comparator{*this, aStartOffset, aEndOffset, &cache};
-  for (auto iter = ancestorSelections.ConstIter(); !iter.Done(); iter.Next()) {
+  for (Selection* selection : ancestorSelections) {
-    Selection* selection = iter.Get()->GetKey();
     // Binary search the sorted ranges in this selection.
     // (Selection::GetRangeAt returns its ranges ordered).
     size_t low = 0;
@@ -1828,19 +1827,18 @@ ConvertNodesOrStringsIntoNode(const Sequence<OwningNodeOrString>& aNodes,
   return fragment.forget();
 }
 
-static void InsertNodesIntoHashset(
+static void InsertNodesIntoHashset(const Sequence<OwningNodeOrString>& aNodes,
-    const Sequence<OwningNodeOrString>& aNodes,
+                                   nsTHashSet<nsINode*>& aHashset) {
-    nsTHashtable<nsPtrHashKey<nsINode>>& aHashset) {
   for (const auto& node : aNodes) {
     if (node.IsNode()) {
-      aHashset.PutEntry(node.GetAsNode());
+      aHashset.Insert(node.GetAsNode());
     }
   }
 }
 
 static nsINode* FindViablePreviousSibling(
     const nsINode& aNode, const Sequence<OwningNodeOrString>& aNodes) {
-  nsTHashtable<nsPtrHashKey<nsINode>> nodeSet(16);
+  nsTHashSet<nsINode*> nodeSet(16);
   InsertNodesIntoHashset(aNodes, nodeSet);
 
   nsINode* viablePreviousSibling = nullptr;
@@ -1857,7 +1855,7 @@ static nsINode* FindViablePreviousSibling(
 
 static nsINode* FindViableNextSibling(
     const nsINode& aNode, const Sequence<OwningNodeOrString>& aNodes) {
-  nsTHashtable<nsPtrHashKey<nsINode>> nodeSet(16);
+  nsTHashSet<nsINode*> nodeSet(16);
   InsertNodesIntoHashset(aNodes, nodeSet);
 
   nsINode* viableNextSibling = nullptr;

dom/base/nsRange.h

@@ -351,8 +351,6 @@ class nsRange final : public mozilla::dom::AbstractRange,
    */
   MOZ_CAN_RUN_SCRIPT void NotifySelectionListenersAfterRangeSet();
 
-  typedef nsTHashtable<nsPtrHashKey<nsRange>> RangeHashTable;
-
  protected:
   /**
    * https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor

dom/base/nsTreeSanitizer.cpp

@@ -1492,37 +1492,37 @@ void nsTreeSanitizer::InitializeStatics() {
 
   sElementsHTML = new AtomsTable(ArrayLength(kElementsHTML));
   for (uint32_t i = 0; kElementsHTML[i]; i++) {
-    sElementsHTML->PutEntry(kElementsHTML[i]);
+    sElementsHTML->Insert(kElementsHTML[i]);
   }
 
   sAttributesHTML = new AtomsTable(ArrayLength(kAttributesHTML));
   for (uint32_t i = 0; kAttributesHTML[i]; i++) {
-    sAttributesHTML->PutEntry(kAttributesHTML[i]);
+    sAttributesHTML->Insert(kAttributesHTML[i]);
   }
 
   sPresAttributesHTML = new AtomsTable(ArrayLength(kPresAttributesHTML));
   for (uint32_t i = 0; kPresAttributesHTML[i]; i++) {
-    sPresAttributesHTML->PutEntry(kPresAttributesHTML[i]);
+    sPresAttributesHTML->Insert(kPresAttributesHTML[i]);
   }
 
   sElementsSVG = new AtomsTable(ArrayLength(kElementsSVG));
   for (uint32_t i = 0; kElementsSVG[i]; i++) {
-    sElementsSVG->PutEntry(kElementsSVG[i]);
+    sElementsSVG->Insert(kElementsSVG[i]);
   }
 
   sAttributesSVG = new AtomsTable(ArrayLength(kAttributesSVG));
   for (uint32_t i = 0; kAttributesSVG[i]; i++) {
-    sAttributesSVG->PutEntry(kAttributesSVG[i]);
+    sAttributesSVG->Insert(kAttributesSVG[i]);
   }
 
   sElementsMathML = new AtomsTable(ArrayLength(kElementsMathML));
   for (uint32_t i = 0; kElementsMathML[i]; i++) {
-    sElementsMathML->PutEntry(kElementsMathML[i]);
+    sElementsMathML->Insert(kElementsMathML[i]);
   }
 
   sAttributesMathML = new AtomsTable(ArrayLength(kAttributesMathML));
   for (uint32_t i = 0; kAttributesMathML[i]; i++) {
-    sAttributesMathML->PutEntry(kAttributesMathML[i]);
+    sAttributesMathML->Insert(kAttributesMathML[i]);
   }
 
   nsCOMPtr<nsIPrincipal> principal =

dom/base/nsTreeSanitizer.h

@@ -8,7 +8,7 @@
 #include "nsAtom.h"
 #include "nsHashKeys.h"
 #include "nsIPrincipal.h"
-#include "nsTHashtable.h"
+#include "nsTHashSet.h"
 
 class nsIContent;
 class nsINode;
@@ -102,10 +102,10 @@ class MOZ_STACK_CLASS nsTreeSanitizer {
   /**
    * We have various tables of static atoms for elements and attributes.
    */
-  class AtomsTable : public nsTHashtable<nsPtrHashKey<const nsStaticAtom>> {
+  class AtomsTable : public nsTHashSet<const nsStaticAtom*> {
    public:
     explicit AtomsTable(uint32_t aLength)
-        : nsTHashtable<nsPtrHashKey<const nsStaticAtom>>(aLength) {}
+        : nsTHashSet<const nsStaticAtom*>(aLength) {}
 
     bool Contains(nsAtom* aAtom) {
       // Because this table only contains static atoms, if aAtom isn't

dom/base/nsWindowMemoryReporter.cpp

@@ -207,7 +207,7 @@ static void ReportCount(const nsCString& aBasePath, const char* aPathTail,
 
 static void CollectWindowReports(nsGlobalWindowInner* aWindow,
                                  nsWindowSizes* aWindowTotalSizes,
-                                 nsTHashtable<nsUint64HashKey>* aGhostWindowIDs,
+                                 nsTHashSet<uint64_t>* aGhostWindowIDs,
                                  WindowPaths* aWindowPaths,
                                  WindowPaths* aTopWindowPaths,
                                  nsIHandleReportCallback* aHandleReport,
@@ -502,19 +502,13 @@ nsWindowMemoryReporter::CollectReports(nsIHandleReportCallback* aHandleReport,
     windows.AppendElement(entry.GetData());
   }
 
-  // Get the IDs of all the "ghost" windows, and call aHandleReport->Callback()
+  // Get the IDs of all the "ghost" windows, and call
-  // for each one.
+  // aHandleReport->Callback() for each one.
-  nsTHashtable<nsUint64HashKey> ghostWindows;
+  nsTHashSet<uint64_t> ghostWindows;
   CheckForGhostWindows(&ghostWindows);
-  for (auto iter = ghostWindows.ConstIter(); !iter.Done(); iter.Next()) {
-    nsGlobalWindowInner::InnerWindowByIdTable* windowsById =
-        nsGlobalWindowInner::GetWindowsTable();
-    if (!windowsById) {
-      NS_WARNING("Couldn't get window-by-id hashtable?");
-      continue;
-    }
 
-    nsGlobalWindowInner* window = windowsById->Get(iter.Get()->GetKey());
+  for (const auto& key : ghostWindows) {
+    nsGlobalWindowInner* window = windowsById->Get(key);
     if (!window) {
       NS_WARNING("Could not look up window?");
       continue;
@@ -787,7 +781,7 @@ void nsWindowMemoryReporter::ObserveAfterMinimizeMemoryUsage() {
  * all ghost windows we found.
  */
 void nsWindowMemoryReporter::CheckForGhostWindows(
-    nsTHashtable<nsUint64HashKey>* aOutGhostIDs /* = nullptr */) {
+    nsTHashSet<uint64_t>* aOutGhostIDs /* = nullptr */) {
   nsGlobalWindowInner::InnerWindowByIdTable* windowsById =
       nsGlobalWindowInner::GetWindowsTable();
   if (!windowsById) {
@@ -798,8 +792,7 @@ void nsWindowMemoryReporter::CheckForGhostWindows(
   mLastCheckForGhostWindows = TimeStamp::NowLoRes();
   KillCheckTimer();
 
-  nsTHashtable<nsPtrHashKey<BrowsingContextGroup>>
+  nsTHashSet<BrowsingContextGroup*> nonDetachedBrowsingContextGroups;
-      nonDetachedBrowsingContextGroups;
 
   // Populate nonDetachedBrowsingContextGroups.
   for (const auto& entry : *windowsById) {
@@ -813,8 +806,7 @@ void nsWindowMemoryReporter::CheckForGhostWindows(
       continue;
     }
 
-    nonDetachedBrowsingContextGroups.PutEntry(
+    nonDetachedBrowsingContextGroups.Insert(window->GetBrowsingContextGroup());
-        window->GetBrowsingContextGroup());
   }
 
   // Update mDetachedWindows and write the ghost window IDs into aOutGhostIDs,
@@ -852,7 +844,7 @@ void nsWindowMemoryReporter::CheckForGhostWindows(
     BrowsingContextGroup* browsingContextGroup =
         window->GetBrowsingContextGroup();
     if (browsingContextGroup &&
-        nonDetachedBrowsingContextGroups.GetEntry(browsingContextGroup)) {
+        nonDetachedBrowsingContextGroups.Contains(browsingContextGroup)) {
       // This window is in the same browsing context group as a non-detached
       // window, so reset its clock.
       timeStamp = TimeStamp();
@@ -867,7 +859,7 @@ void nsWindowMemoryReporter::CheckForGhostWindows(
         // that is not null.
         mGhostWindowCount++;
         if (aOutGhostIDs && window) {
-          aOutGhostIDs->PutEntry(window->WindowID());
+          aOutGhostIDs->Insert(window->WindowID());
         }
       }
     }
@@ -910,16 +902,16 @@ void nsWindowMemoryReporter::UnlinkGhostWindows() {
   }
 
   // Get the IDs of all the "ghost" windows, and unlink them all.
-  nsTHashtable<nsUint64HashKey> ghostWindows;
+  nsTHashSet<uint64_t> ghostWindows;
   sWindowReporter->CheckForGhostWindows(&ghostWindows);
-  for (auto iter = ghostWindows.ConstIter(); !iter.Done(); iter.Next()) {
+  for (const auto& key : ghostWindows) {
     nsGlobalWindowInner::InnerWindowByIdTable* windowsById =
         nsGlobalWindowInner::GetWindowsTable();
     if (!windowsById) {
       continue;
     }
 
-    RefPtr<nsGlobalWindowInner> window = windowsById->Get(iter.Get()->GetKey());
+    RefPtr<nsGlobalWindowInner> window = windowsById->Get(key);
     if (window) {
       window->RiskyUnlink();
     }

dom/base/nsWindowMemoryReporter.h

@@ -12,6 +12,7 @@
 #include "nsIObserver.h"
 #include "nsITimer.h"
 #include "nsTHashMap.h"
+#include "nsTHashSet.h"
 #include "nsWeakReference.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Assertions.h"
@@ -132,8 +133,7 @@ class nsWindowMemoryReporter final : public nsIMemoryReporter,
    * This is called asynchronously after we observe a DOM window being detached
    * from its docshell, and also right before we generate a memory report.
    */
-  void CheckForGhostWindows(
+  void CheckForGhostWindows(nsTHashSet<uint64_t>* aOutGhostIDs = nullptr);
-      nsTHashtable<nsUint64HashKey>* aOutGhostIDs = nullptr);
 
   /**
    * Eventually do a check for ghost windows, if we haven't done one recently

dom/base/nsWindowRoot.cpp

@@ -280,8 +280,7 @@ nsresult nsWindowRoot::GetControllerForCommand(const char* aCommand,
 }
 
 void nsWindowRoot::GetEnabledDisabledCommandsForControllers(
-    nsIControllers* aControllers,
+    nsIControllers* aControllers, nsTHashSet<nsCString>& aCommandsHandled,
-    nsTHashtable<nsCStringHashKey>& aCommandsHandled,
     nsTArray<nsCString>& aEnabledCommands,
     nsTArray<nsCString>& aDisabledCommands) {
   uint32_t controllerCount;
@@ -322,7 +321,7 @@ void nsWindowRoot::GetEnabledDisabledCommandsForControllers(
 void nsWindowRoot::GetEnabledDisabledCommands(
     nsTArray<nsCString>& aEnabledCommands,
     nsTArray<nsCString>& aDisabledCommands) {
-  nsTHashtable<nsCStringHashKey> commandsHandled;
+  nsTHashSet<nsCString> commandsHandled;
 
   nsCOMPtr<nsIControllers> controllers;
   GetControllers(false, getter_AddRefs(controllers));
@@ -367,20 +366,20 @@ JSObject* nsWindowRoot::WrapObject(JSContext* aCx,
 
 void nsWindowRoot::AddBrowser(nsIRemoteTab* aBrowser) {
   nsWeakPtr weakBrowser = do_GetWeakReference(aBrowser);
-  mWeakBrowsers.PutEntry(weakBrowser);
+  mWeakBrowsers.Insert(weakBrowser);
 }
 
 void nsWindowRoot::RemoveBrowser(nsIRemoteTab* aBrowser) {
   nsWeakPtr weakBrowser = do_GetWeakReference(aBrowser);
-  mWeakBrowsers.RemoveEntry(weakBrowser);
+  mWeakBrowsers.Remove(weakBrowser);
 }
 
 void nsWindowRoot::EnumerateBrowsers(BrowserEnumerator aEnumFunc, void* aArg) {
   // Collect strong references to all browsers in a separate array in
   // case aEnumFunc alters mWeakBrowsers.
   nsTArray<nsCOMPtr<nsIRemoteTab>> remoteTabs;
-  for (auto iter = mWeakBrowsers.ConstIter(); !iter.Done(); iter.Next()) {
+  for (const auto& key : mWeakBrowsers) {
-    nsCOMPtr<nsIRemoteTab> remoteTab(do_QueryReferent(iter.Get()->GetKey()));
+    nsCOMPtr<nsIRemoteTab> remoteTab(do_QueryReferent(key));
     if (remoteTab) {
       remoteTabs.AppendElement(remoteTab);
     }

dom/base/nsWindowRoot.h

@@ -14,7 +14,7 @@ class nsIGlobalObject;
 #include "nsIWeakReferenceUtils.h"
 #include "nsPIWindowRoot.h"
 #include "nsCycleCollectionParticipant.h"
-#include "nsTHashtable.h"
+#include "nsTHashSet.h"
 #include "nsHashKeys.h"
 
 class nsWindowRoot final : public nsPIWindowRoot {
@@ -77,8 +77,7 @@ class nsWindowRoot final : public nsPIWindowRoot {
   virtual ~nsWindowRoot();
 
   void GetEnabledDisabledCommandsForControllers(
-      nsIControllers* aControllers,
+      nsIControllers* aControllers, nsTHashSet<nsCString>& aCommandsHandled,
-      nsTHashtable<nsCStringHashKey>& aCommandsHandled,
       nsTArray<nsCString>& aEnabledCommands,
       nsTArray<nsCString>& aDisabledCommands);
 
@@ -95,7 +94,7 @@ class nsWindowRoot final : public nsPIWindowRoot {
 
   // The BrowserParents that are currently registered with this top-level
   // window.
-  typedef nsTHashtable<nsRefPtrHashKey<nsIWeakReference>> WeakBrowserTable;
+  typedef nsTHashSet<RefPtr<nsIWeakReference>> WeakBrowserTable;
   WeakBrowserTable mWeakBrowsers;
 };
 

layout/style/ServoStyleSet.cpp

@@ -130,8 +130,7 @@ nsPresContext* ServoStyleSet::GetPresContext() {
 template <typename Functor>
 static void EnumerateShadowRoots(const Document& aDoc, const Functor& aCb) {
   const Document::ShadowRootSet& shadowRoots = aDoc.ComposedShadowRoots();
-  for (auto iter = shadowRoots.ConstIter(); !iter.Done(); iter.Next()) {
+  for (ShadowRoot* root : shadowRoots) {
-    ShadowRoot* root = iter.Get()->GetKey();
     MOZ_ASSERT(root);
     MOZ_DIAGNOSTIC_ASSERT(root->IsInComposedDoc());
     aCb(*root);