Delete background tab IOSurfaces on Mac.

content/browser/renderer_host/render_widget_host_view_gtk.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_GTK_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_GTK_H_
 #pragma once
 
 #include <gdk/gdk.h>
 
@@ skipping 90 matching lines @@
       skia::PlatformCanvas* output,
       base::Callback<void(bool)> callback) OVERRIDE;
   virtual void OnAcceleratedCompositingStateChange() OVERRIDE;
   virtual void AcceleratedSurfaceBuffersSwapped(
       const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params,
       int gpu_host_id) OVERRIDE;
   virtual void AcceleratedSurfacePostSubBuffer(
       const GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params& params,
       int gpu_host_id) OVERRIDE;
   virtual void AcceleratedSurfaceSuspend() OVERRIDE;
+  virtual bool HasAcceleratedSurface(const gfx::Size& desired_size) OVERRIDE;
   virtual void CreatePluginContainer(gfx::PluginWindowHandle id) OVERRIDE;
   virtual void DestroyPluginContainer(gfx::PluginWindowHandle id) OVERRIDE;
   virtual void ProcessTouchAck(WebKit::WebInputEvent::Type type,
                                bool processed) OVERRIDE;
   virtual void SetHasHorizontalScrollbar(
       bool has_horizontal_scrollbar) OVERRIDE;
   virtual void SetScrollOffsetPinning(
       bool is_pinned_to_left, bool is_pinned_to_right) OVERRIDE;
   virtual void GetScreenInfo(WebKit::WebScreenInfo* results) OVERRIDE;
   virtual gfx::Rect GetRootWindowBounds() OVERRIDE;
@@ skipping 162 matching lines @@
   gfx::PluginWindowHandle compositing_surface_;
 
   // The event for the last mouse down we handled. We need this for context
   // menus and drags.
   GdkEventButton* last_mouse_down_;
 
   ui::GtkSignalRegistrar signals_;
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_GTK_H_