Remove the acceleratedCompositingForCanvas setting.

Source/core/rendering/RenderEmbeddedObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2010 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 190 matching lines @@
         frameView()->addWidgetToUpdate(*this);
 
     clearNeedsLayout();
 }
 
 bool RenderEmbeddedObject::scroll(ScrollDirection direction, ScrollGranularity granularity, float)
 {
     return false;
 }
 
-CompositingReasons RenderEmbeddedObject::additionalCompositingReasons(CompositingTriggerFlags triggers) const
+CompositingReasons RenderEmbeddedObject::additionalCompositingReasons() const
 {
     if (requiresAcceleratedCompositing())
         return CompositingReasonPlugin;
     return CompositingReasonNone;
 }
 
 RenderBox* RenderEmbeddedObject::embeddedContentBox() const
 {
     if (!node() || !widget() || !widget()->isFrameView())
         return 0;
     return toFrameView(widget())->embeddedContentBox();
 }
 
 }