Oilpan: move ImageData to the oilpan heap.

Source/core/html/canvas/WebGLRenderingContextBase.h

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 315 matching lines @@
 
     blink::WebGraphicsContext3D* webGraphicsContext3D() const { return m_context.get(); }
     WebGLContextGroup* contextGroup() const { return m_contextGroup.get(); }
     virtual blink::WebLayer* platformLayer() const OVERRIDE;
     Extensions3DUtil* extensionsUtil();
 
     void reshape(int width, int height);
 
     void markLayerComposited();
     virtual void paintRenderingResultsToCanvas() OVERRIDE;
-    PassRefPtr<ImageData> paintRenderingResultsToImageData();
+    PassRefPtrWillBeRawPtr<ImageData> paintRenderingResultsToImageData();
 
     void removeSharedObject(WebGLSharedObject*);
     void removeContextObject(WebGLContextObject*);
 
     unsigned maxVertexAttribs() const { return m_maxVertexAttribs; }
 
     // ActiveDOMObject notifications
     virtual bool hasPendingActivity() const OVERRIDE;
     virtual void stop() OVERRIDE;
 
@@ skipping 568 matching lines @@
     // If the vector is empty, return the maximum allowed active context number.
     static size_t oldestContextIndex();
     static IntSize oldestContextSize();
 };
 
 DEFINE_TYPE_CASTS(WebGLRenderingContextBase, CanvasRenderingContext, context, context->is3d(), context.is3d());
 
 } // namespace WebCore
 
 #endif // WebGLRenderingContextBase_h