Move iframe and plugin compositing triggers into additionalCompositingReasons

Source/core/rendering/RenderEmbeddedObject.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 57 matching lines @@
     virtual LayerType layerTypeRequired() const OVERRIDE FINAL;
 
     virtual bool scroll(ScrollDirection, ScrollGranularity, float multiplier) OVERRIDE FINAL;
 
     bool getReplacementTextGeometry(const LayoutPoint& accumulatedOffset, FloatRect& contentRect, Path&, FloatRect& replacementTextRect, Font&, TextRun&, float& textWidth) const;
 
     virtual bool canHaveChildren() const OVERRIDE FINAL;
     virtual RenderObjectChildList* virtualChildren() OVERRIDE FINAL { return children(); }
     virtual const RenderObjectChildList* virtualChildren() const OVERRIDE FINAL { return children(); }
 
+    virtual CompositingReasons additionalCompositingReasons(CompositingTriggerFlags) const OVERRIDE;
+
     bool m_hasFallbackContent; // FIXME: This belongs on HTMLObjectElement.
 
     bool m_showsUnavailablePluginIndicator;
     PluginUnavailabilityReason m_pluginUnavailabilityReason;
     String m_unavailablePluginReplacementText;
     RenderObjectChildList m_children;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderEmbeddedObject, isEmbeddedObject());
 
 } // namespace WebCore
 
 #endif // RenderEmbeddedObject_h