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

Source/core/html/canvas/WebGLRenderbuffer.h

Index: Source/core/html/canvas/WebGLRenderbuffer.h
diff --git a/Source/core/html/canvas/WebGLRenderbuffer.h b/Source/core/html/canvas/WebGLRenderbuffer.h
index 9b22af455a0b9a8a48a3bcda5c268081f0ff476e..bdddacbf942a3a0614a71b13861e29edd9ccea2a 100644
--- a/Source/core/html/canvas/WebGLRenderbuffer.h
+++ b/Source/core/html/canvas/WebGLRenderbuffer.h
@@ -36,7 +36,7 @@ class WebGLRenderbuffer FINAL : public WebGLSharedObject, public ScriptWrappable
 public:
     virtual ~WebGLRenderbuffer();
 
-    static PassRefPtr<WebGLRenderbuffer> create(WebGLRenderingContextBase*);
+    static PassRefPtrWillBeRawPtr<WebGLRenderbuffer> create(WebGLRenderingContextBase*);
 
     void setInternalFormat(GLenum internalformat)
     {
@@ -56,10 +56,12 @@ public:
 
     void setHasEverBeenBound() { m_hasEverBeenBound = true; }
 
-    void setEmulatedStencilBuffer(PassRefPtr<WebGLRenderbuffer> buffer) { m_emulatedStencilBuffer = buffer; }
+    void setEmulatedStencilBuffer(PassRefPtrWillBeRawPtr<WebGLRenderbuffer> buffer) { m_emulatedStencilBuffer = buffer; }
     WebGLRenderbuffer* emulatedStencilBuffer() const { return m_emulatedStencilBuffer.get(); }
     void deleteEmulatedStencilBuffer(blink::WebGraphicsContext3D* context3d);
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 protected:
     WebGLRenderbuffer(WebGLRenderingContextBase*);
 
@@ -73,7 +75,7 @@ private:
 
     bool m_hasEverBeenBound;
 
-    RefPtr<WebGLRenderbuffer> m_emulatedStencilBuffer;
+    RefPtrWillBeMember<WebGLRenderbuffer> m_emulatedStencilBuffer;
 };
 
 } // namespace WebCore