Get windowless plugins working when accelerated compositing is turned on.

content/plugin/webplugin_proxy.h

Index: content/plugin/webplugin_proxy.h
===================================================================
--- content/plugin/webplugin_proxy.h	(revision 166499)
+++ content/plugin/webplugin_proxy.h	(working copy)
@@ -119,9 +119,7 @@
                       const gfx::Rect& clip_rect,
                       const TransportDIB::Handle& windowless_buffer0,
                       const TransportDIB::Handle& windowless_buffer1,
-                      int windowless_buffer_index,
-                      const TransportDIB::Handle& background_buffer,
-                      bool transparent);
+                      int windowless_buffer_index);
   virtual void CancelDocumentLoad() OVERRIDE;
   virtual void InitiateHTTPRangeRequest(
       const char* url, const char* range_info, int range_request_id) OVERRIDE;
@@ -240,7 +238,6 @@
   // Updates the shared memory sections where windowless plugins paint.
   void SetWindowlessBuffers(const TransportDIB::Handle& windowless_buffer0,
                             const TransportDIB::Handle& windowless_buffer1,
-                            const TransportDIB::Handle& background_buffer,
                             const gfx::Rect& window_rect);
 
 #if defined(OS_MACOSX)
@@ -279,21 +276,16 @@
   // fields are for the front-buffer and back-buffer of a buffer flipping system
   // and windowless_buffer_index_ identifies which set we are using as the
   // back-buffer at any given time.
-  bool transparent_;
   int windowless_buffer_index_;
 #if defined(OS_MACOSX)
   scoped_ptr<TransportDIB> windowless_dibs_[2];
-  scoped_ptr<TransportDIB> background_dib_;
   base::mac::ScopedCFTypeRef<CGContextRef> windowless_contexts_[2];
-  base::mac::ScopedCFTypeRef<CGContextRef> background_context_;
   scoped_ptr<WebPluginAcceleratedSurfaceProxy> accelerated_surface_;
 #else
   SkAutoTUnref<skia::PlatformCanvas> windowless_canvases_[2];
-  SkAutoTUnref<skia::PlatformCanvas> background_canvas_;
 
 #if defined(USE_X11)
   scoped_refptr<SharedTransportDIB> windowless_dibs_[2];
-  scoped_refptr<SharedTransportDIB> background_dib_;
   // If we can use SHM pixmaps for windowless plugin painting or not.
   bool use_shm_pixmap_;
   // The SHM pixmaps for windowless plugin painting.