Oilpan: Prepare to move AXObjectCache to the heap

Source/core/dom/AXObjectCache.h

Index: Source/core/dom/AXObjectCache.h
diff --git a/Source/core/dom/AXObjectCache.h b/Source/core/dom/AXObjectCache.h
index 0ffd1fc273f5ca4bd408b319f49b8d2f9bfd5e44..8fae9c3744eae97ea96b834c15c2f3dbdc62f5c3 100644
--- a/Source/core/dom/AXObjectCache.h
+++ b/Source/core/dom/AXObjectCache.h
@@ -40,14 +40,16 @@ class LayoutMenuList;
 class Page;
 class Widget;
 
-class CORE_EXPORT AXObjectCache {
-    WTF_MAKE_NONCOPYABLE(AXObjectCache); WTF_MAKE_FAST_ALLOCATED(AXObjectCache);
+class CORE_EXPORT AXObjectCache : public NoBaseWillBeGarbageCollectedFinalized<AXObjectCache> {
+    WTF_MAKE_NONCOPYABLE(AXObjectCache);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(AXObjectCache);
 public:
-    static PassOwnPtr<AXObjectCache> create(Document&);
+    static PassOwnPtrWillBeRawPtr<AXObjectCache> create(Document&);
 
     static AXObject* focusedUIElementForPage(const Page*);
 
     virtual ~AXObjectCache();
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
 
     enum AXNotification {
         AXActiveDescendantChanged,
@@ -81,6 +83,8 @@ public:
         AXValueChanged
     };
 
+    virtual void dispose() = 0;
+
     virtual void selectionChanged(Node*) = 0;
     virtual void childrenChanged(Node*) = 0;
     virtual void childrenChanged(LayoutObject*) = 0;
@@ -131,7 +135,7 @@ public:
     virtual const AtomicString& computedRoleForNode(Node*) = 0;
     virtual String computedNameForNode(Node*) = 0;
 
-    typedef PassOwnPtr<AXObjectCache> (*AXObjectCacheCreateFunction)(Document&);
+    typedef PassOwnPtrWillBeRawPtr<AXObjectCache> (*AXObjectCacheCreateFunction)(Document&);
     static void init(AXObjectCacheCreateFunction);
 
 protected:
@@ -145,14 +149,17 @@ class CORE_EXPORT ScopedAXObjectCache {
     WTF_MAKE_NONCOPYABLE(ScopedAXObjectCache);
 public:
     static PassOwnPtr<ScopedAXObjectCache> create(Document&);
+    ~ScopedAXObjectCache();
+
+    void dispose();
 
     AXObjectCache* get();
 
 private:
     explicit ScopedAXObjectCache(Document&);
 
-    OwnPtr<AXObjectCache> m_ownedCache;
-    AXObjectCache* m_cache;
+    OwnPtrWillBePersistent<AXObjectCache> m_ownedCache;
+    RawPtrWillBePersistent<AXObjectCache> m_cache;

[haraken, 2015/05/29 09:16:19]

RawPtrWillBePersistent is a bit concerning since it has a risk of producing
leaks.

Just help me understand: In non-oilpan, why is it safe to hold a raw pointer to
AXObjectCache? How is it guaranteed that Document is not disposed while the
ScopedAXObjectCache is holding the raw pointer?

[keishi, 2015/06/08 06:27:52]

ScopedAXObjectCache and WebScopedAXContext is only used immediately after
creation so it looks safe but I think we can do something like
https://codereview.chromium.org/1167983002/ to remove the raw pointer member to
AXObjectCache.

 };
 
 }