Remove dead code related to compositing from Sky

sky/engine/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 272 matching lines @@
     }
 
     HashSet<RawPtr<CanvasObserver> >::iterator end = m_observers.end();
     for (HashSet<RawPtr<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
         (*it)->canvasResized(this);
 }
 
 bool HTMLCanvasElement::paintsIntoCanvasBuffer() const
 {
     ASSERT(m_context);
-
-    if (!m_context->isAccelerated())
-        return true;
-
-    if (renderBox() && renderBox()->hasAcceleratedCompositing())
-        return false;
-
     return true;
 }
 
-
 void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r)
 {
     if (m_context) {
         if (!paintsIntoCanvasBuffer())
             return;
         m_context->paintRenderingResultsToCanvas();
     }
 
     if (hasImageBuffer()) {
         ImageBuffer* imageBuffer = buffer();
@@ skipping 344 matching lines @@
     }
     return m_imageBuffer->copyImage(DontCopyBackingStore, Unscaled);
 }
 
 FloatSize HTMLCanvasElement::sourceSize() const
 {
     return FloatSize(width(), height());
 }
 
 }