Oilpan: move 2D Canvas and WebGL objects to the heap.

Source/core/html/canvas/CanvasContextAttributes.h

Index: Source/core/html/canvas/CanvasContextAttributes.h
diff --git a/Source/core/html/canvas/CanvasContextAttributes.h b/Source/core/html/canvas/CanvasContextAttributes.h
index 912864a6123a4470e66e818603de0510bee10bda..a83e34e3bc851a6456f7d7df113f5da09c52d133 100644
--- a/Source/core/html/canvas/CanvasContextAttributes.h
+++ b/Source/core/html/canvas/CanvasContextAttributes.h
@@ -27,6 +27,7 @@
 #ifndef CanvasContextAttributes_h
 #define CanvasContextAttributes_h
 
+#include "platform/heap/Handle.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
@@ -34,10 +35,12 @@ namespace WebCore {
 // A base class for any attributes that are needed which would affect
 // the creation of the Canvas's rendering context.
 
-class CanvasContextAttributes : public RefCounted<CanvasContextAttributes> {
+class CanvasContextAttributes : public RefCountedWillBeGarbageCollectedFinalized<CanvasContextAttributes> {

[haraken, 2014/07/03 04:40:29]

Can we probably drop Finalized?

[sof, 2014/07/03 07:25:48]

Yes, the classes that derive from it (WebGLContextAttributes and
Canvas2DContextAttributes) do not need finalization.

   public:
     virtual ~CanvasContextAttributes();
 
+    virtual void trace(Visitor*) { }
+
   protected:
     CanvasContextAttributes();
 };