Let every "accelerated IO surface swapped" message have an identifier of the surface.

chrome/renderer/webplugin_delegate_proxy.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_WEBPLUGIN_DELEGATE_PROXY_H_
 #define CHROME_RENDERER_WEBPLUGIN_DELEGATE_PROXY_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 158 matching lines @@
                                         int32 width,
                                         int32 height,
                                         uint64 io_surface_identifier);
   void OnAcceleratedSurfaceSetTransportDIB(gfx::PluginWindowHandle window,
                                            int32 width,
                                            int32 height,
                                            TransportDIB::Handle transport_dib);
   void OnAcceleratedSurfaceAllocTransportDIB(size_t size,
                                              TransportDIB::Handle* dib_handle);
   void OnAcceleratedSurfaceFreeTransportDIB(TransportDIB::Id dib_id);
-  void OnAcceleratedSurfaceBuffersSwapped(gfx::PluginWindowHandle window);
+  void OnAcceleratedSurfaceBuffersSwapped(gfx::PluginWindowHandle window,
+                                          uint64 surface_id);
 #endif
 
   // Draw a graphic indicating a crashed plugin.
   void PaintSadPlugin(WebKit::WebCanvas* canvas, const gfx::Rect& rect);
 
   // Returns true if the given rectangle is different in the native drawing
   // context and the current background bitmap.
   bool BackgroundChanged(gfx::NativeDrawingContext context,
                          const gfx::Rect& rect);
 
@@ skipping 81 matching lines @@
   // This lets us know which portion of the backing store has been painted into.
   gfx::Rect backing_store_painted_;
 
   // The url of the main frame hosting the plugin.
   GURL page_url_;
 
   DISALLOW_COPY_AND_ASSIGN(WebPluginDelegateProxy);
 };
 
 #endif  // CHROME_RENDERER_WEBPLUGIN_DELEGATE_PROXY_H_