Revert of Accelerate small canvases if Ganesh is on. (https://codereview.chromium.org/326283002/)

Reason for revert:
Need to revert the blink side and this (incorrectly) adds an OVERRIDE for a cross-repository override.

Original issue's description:
> Accelerate small canvases if Ganesh is on.
>
> cc side of change.
>
> TBR=phajdan.jr@chromium.org
> BUG=382738
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276753

TBR=ajuma@chromium.org,kbr@chromium.org,phajdan.jr@chromium.org,chrishtr@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=382738

Review URL: https://codereview.chromium.org/349733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278842 0039d316-1c4b-4281-b951-d872f2087c98

content/renderer/gpu/render_widget_compositor.cc

@@ -709,8 +709,4 @@ void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
-bool RenderWidgetCompositor::usesGpuRasterization() {
-  return layer_tree_host_->UseGpuRasterization();
-}
-
 }  // namespace content

content/renderer/gpu/render_widget_compositor.h

@@ -120,7 +120,6 @@ class RenderWidgetCompositor : public blink::WebLayerTreeView,
   virtual void setShowDebugBorders(bool show);
   virtual void setContinuousPaintingEnabled(bool enabled);
   virtual void setShowScrollBottleneckRects(bool show);
-  virtual bool usesGpuRasterization() OVERRIDE;
 
   // cc::LayerTreeHostClient implementation.
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE;

content/test/web_layer_tree_view_impl_for_testing.cc

@@ -167,8 +167,4 @@ void WebLayerTreeViewImplForTesting::clearViewportLayers() {
                                            scoped_refptr<cc::Layer>());
 }
 
-bool WebLayerTreeViewImplForTesting::usesGpuRasterization() {
-  return false;
-}
-
 }  // namespace content

content/test/web_layer_tree_view_impl_for_testing.h

@@ -59,7 +59,6 @@ class WebLayerTreeViewImplForTesting
       const blink::WebLayer* innerViewportScrollLayer,
       const blink::WebLayer* outerViewportScrollLayer) OVERRIDE;
   virtual void clearViewportLayers() OVERRIDE;
-  virtual bool usesGpuRasterization() OVERRIDE;
 
   // cc::LayerTreeHostClient implementation.
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE {}