Refactor how surfaces are acquired for GPU compositing.

chrome/browser/renderer_host/render_widget_host_view_gtk.h

Index: chrome/browser/renderer_host/render_widget_host_view_gtk.h
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.h b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
index b354a7ba4dd933ff12c91ec6d48d497b5286883f..6854067dae829e5ae07e24854e7545276a20479e 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
@@ -90,7 +90,10 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView,
   virtual void DestroyPluginContainer(gfx::PluginWindowHandle id);
   virtual void SetVisuallyDeemphasized(const SkColor* color, bool animate);
   virtual bool ContainsNativeView(gfx::NativeView native_view) const;
+
   virtual void AcceleratedCompositingActivated(bool activated);
+  virtual gfx::PluginWindowHandle AcquireCompositingSurface();
+  virtual void ReleaseCompositingSurface(gfx::PluginWindowHandle surface);
 
   // ui::AnimationDelegate implementation.
   virtual void AnimationEnded(const ui::Animation* animation);
@@ -224,6 +227,8 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView,
   // indicate the top edge, positive the bottom.
   int dragged_at_vertical_edge_;
 
+  bool accelerated_surface_acquired_;
+
 #if defined(OS_CHROMEOS)
   // Custimized tooltip window.
   scoped_ptr<views::TooltipWindowGtk> tooltip_window_;