Mac: Correctly show/hide compositor on navigations.

chrome/browser/renderer_host/render_widget_host_view_mac.h

 // Copyright (c) 2006-2008 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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #pragma once
 
 #import <Cocoa/Cocoa.h>
 #import <QuartzCore/CALayer.h>
@@ skipping 217 matching lines @@
   virtual void AcceleratedSurfaceSetIOSurface(gfx::PluginWindowHandle window,
                                               int32 width,
                                               int32 height,
                                               uint64 io_surface_identifier);
   virtual void AcceleratedSurfaceSetTransportDIB(
       gfx::PluginWindowHandle window,
       int32 width,
       int32 height,
       TransportDIB::Handle transport_dib);
   virtual void AcceleratedSurfaceBuffersSwapped(gfx::PluginWindowHandle window);
+  virtual void GpuRenderingStateDidChange();
   void DrawAcceleratedSurfaceInstance(
       CGLContextObj context, gfx::PluginWindowHandle plugin_handle);
   // Forces the textures associated with any accelerated plugin instances
   // to be reloaded.
   void ForceTextureReload();
 
   virtual void SetVisuallyDeemphasized(bool deemphasized);
 
   void KillSelf();
 
@@ skipping 83 matching lines @@
   // Whether or not web accessibility is enabled.
   bool renderer_accessible_;
 
   // selected text on the renderer.
   std::string selected_text_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_