Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/Document.h

Index: Source/core/dom/Document.h
diff --git a/Source/core/dom/Document.h b/Source/core/dom/Document.h
index 17fa3c9eb022d6e17b09e0fc6c83c38e63eef3d0..d4c708bd66249477457195f48b904ffe7b69448c 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -215,7 +215,7 @@ typedef unsigned char DocumentClassFlags;
 
 class Document;
 
-class DocumentVisibilityObserver {
+class DocumentVisibilityObserver : public WillBeGarbageCollectedMixin {
 public:
     DocumentVisibilityObserver(Document&);
     virtual ~DocumentVisibilityObserver();
@@ -859,7 +859,7 @@ public:
     void cancelFocusAppearanceUpdate();
 
     // Extension for manipulating canvas drawing contexts for use in CSS
-    void getCSSCanvasContext(const String& type, const String& name, int width, int height, bool&, RefPtr<CanvasRenderingContext2D>&, bool&, RefPtr<WebGLRenderingContext>&);
+    void getCSSCanvasContext(const String& type, const String& name, int width, int height, bool&, RefPtrWillBeRawPtr<CanvasRenderingContext2D>&, bool&, RefPtrWillBeRawPtr<WebGLRenderingContext>&);
     HTMLCanvasElement& getCSSCanvasElement(const String& name);
 
     bool isDNSPrefetchEnabled() const { return m_isDNSPrefetchEnabled; }
@@ -941,7 +941,8 @@ public:
     // Used to allow element that loads data without going through a FrameLoader to delay the 'load' event.
     void incrementLoadEventDelayCount() { ++m_loadEventDelayCount; }
     void decrementLoadEventDelayCount();
-    bool isDelayingLoadEvent() const { return m_loadEventDelayCount; }
+    void checkLoadEventSoon();
+    bool isDelayingLoadEvent();
     void loadPluginsSoon();
 
     PassRefPtrWillBeRawPtr<Touch> createTouch(DOMWindow*, EventTarget*, int identifier, int pageX, int pageY, int screenX, int screenY, int radiusX, int radiusY, float rotationAngle, float force) const;
@@ -1110,6 +1111,8 @@ private:
 
     void detachParser();
 
+    void clearWeakMembers(Visitor*);
+
     virtual bool isDocument() const OVERRIDE FINAL { return true; }
 
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0) OVERRIDE;
@@ -1235,7 +1238,7 @@ private:
     MutationObserverOptions m_mutationObserverTypes;
 
     OwnPtrWillBePersistent<StyleEngine> m_styleEngine;

[haraken, 2014/04/24 04:18:43]

Shouldn't this become a Member?

(We're disabling the plugin check for persistent handles in the Node
hierarchy:-)

[Mads Ager (chromium), 2014/04/24 10:57:36]

Yes, it should. However, I'm afraid that changing that will lead to further
finalization order issues. Addressing those would make this changelist even
larger and more complicated, so I would like to land this first.

Overall, the next step after this change is to start the removal of Persistents
from the Node hierarchy to other nodes. Once that is done we need to implement
full tracing of the node hierarchy (so that we no longer rely on the container
node algorithms to determine when objects are alive in the TreeShared tree.)
Once that is done we can start to use Member pointers *into* the Node hierarchy
as well.

These are big changes and I need to do them in smaller steps; for my own sanity,
but also to keep the changes at a size that can be reviewed. :)

-    RefPtrWillBePersistent<StyleSheetList> m_styleSheetList;
+    RefPtrWillBeMember<StyleSheetList> m_styleSheetList;
 
     OwnPtr<FormController> m_formController;
 
@@ -1376,7 +1379,7 @@ private:
 
     bool m_hasViewportUnits;
 
-    HashSet<DocumentVisibilityObserver*> m_visibilityObservers;
+    WillBeHeapHashSet<RawPtrWillBeWeakMember<DocumentVisibilityObserver> > m_visibilityObservers;
 };
 
 inline void Document::notifyRemovePendingSheetIfNeeded()