Prepare SVGDocumentExtensions::m_elementDependencies for oilpan

Source/core/svg/SVGDocumentExtensions.h

Index: Source/core/svg/SVGDocumentExtensions.h
diff --git a/Source/core/svg/SVGDocumentExtensions.h b/Source/core/svg/SVGDocumentExtensions.h
index 1ceb7ab3a494f38a1df08d364f82a5d0e12ebb9a..e3772c015978ea11b7d3d242a7d8cf7b9c4ccf95 100644
--- a/Source/core/svg/SVGDocumentExtensions.h
+++ b/Source/core/svg/SVGDocumentExtensions.h
@@ -42,6 +42,8 @@ class SVGSMILElement;
 class SVGSVGElement;
 class Element;
 
+typedef WillBeHeapHashSet<RawPtrWillBeMember<SVGElement> > SVGElementSet;
+
 class SVGDocumentExtensions : public NoBaseWillBeGarbageCollectedFinalized<SVGDocumentExtensions> {
     WTF_MAKE_NONCOPYABLE(SVGDocumentExtensions); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
@@ -67,7 +69,7 @@ public:
 
     SVGResourcesCache* resourcesCache() const { return m_resourcesCache.get(); }
 
-    HashSet<SVGElement*>* setOfElementsReferencingTarget(SVGElement* referencedElement) const;
+    SVGElementSet* setOfElementsReferencingTarget(SVGElement* referencedElement) const;
     void addElementReferencingTarget(SVGElement* referencingElement, SVGElement* referencedElement);
     void removeAllTargetReferencesForElement(SVGElement*);
     void rebuildAllElementReferencesForTarget(SVGElement*);
@@ -98,7 +100,7 @@ public:
     void trace(Visitor*);
 
 private:
-    Document* m_document; // weak reference
+    RawPtrWillBeMember<Document> m_document;
     WillBeHeapHashSet<RawPtrWillBeMember<SVGSVGElement> > m_timeContainers; // For SVG 1.2 support this will need to be made more general.
 #if ENABLE(SVG_FONTS)
     WillBeHeapHashSet<RawPtrWillBeMember<SVGFontFaceElement> > m_svgFontFaceElements;
@@ -108,8 +110,11 @@ private:
     HashMap<AtomicString, RenderSVGResourceContainer*> m_resources;
     HashMap<AtomicString, OwnPtr<SVGPendingElements> > m_pendingResources; // Resources that are pending.
     HashMap<AtomicString, OwnPtr<SVGPendingElements> > m_pendingResourcesForRemoval; // Resources that are pending and scheduled for removal.
-    HashMap<SVGElement*, OwnPtr<HashSet<SVGElement*> > > m_elementDependencies;
+    typedef WillBeHeapHashMap<RawPtrWillBeMember<SVGElement>, OwnPtrWillBeMember<SVGElementSet> > ElementDependenciesMap;
+    OwnPtrWillBeMember<ElementDependenciesMap> m_elementDependencies;

[haraken, 2014/06/10 08:48:19]

I wonder why you need to make this an OwnPtrWillBeMember. Doesn't
ElementDependenciesMap work?

[kouhei (in TOK), 2014/06/10 08:58:59]

Done.

     OwnPtr<SVGResourcesCache> m_resourcesCache;
+
+    // FIXME: Oilpan: make below HeapHashSet<WeakMember<SVGSVGElement> >

[haraken, 2014/06/10 08:48:19]

I don't fully understand why this needs to be weak. Given that SVGSVGElements in
this hash set die together with the document, can we use a strong Member for
this?

[kouhei (in TOK), 2014/06/10 08:58:59]

This change was made in https://codereview.chromium.org/323803002/ and this was
landed as a strong ref.

     HashSet<SVGSVGElement*> m_relativeLengthSVGRoots; // Root SVG elements with relative length descendants.
     FloatPoint m_translate;
 #if !ASSERT_DISABLED