Support browser side thumbnailing for GPU composited pages on Windows.

content/browser/renderer_host/render_widget_host_view_mac.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_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #pragma once
 
 #import <Cocoa/Cocoa.h>
 
@@ skipping 175 matching lines @@
   virtual bool IsShowing() OVERRIDE;
   virtual gfx::Rect GetViewBounds() const OVERRIDE;
   virtual void SetShowingContextMenu(bool showing) OVERRIDE;
   virtual void SetActive(bool active) OVERRIDE;
   virtual void SetTakesFocusOnlyOnMouseDown(bool flag) OVERRIDE;
   virtual void SetWindowVisibility(bool visible) OVERRIDE;
   virtual void WindowFrameChanged() OVERRIDE;
   virtual void UnhandledWheelEvent(
       const WebKit::WebMouseWheelEvent& event) OVERRIDE;
   virtual void SetBackground(const SkBitmap& background) OVERRIDE;
+  virtual bool CopyFromCompositingSurface(
+      const gfx::Size& size,
+      skia::PlatformCanvas* output) OVERRIDE;
 
   // Implementation of RenderWidgetHostViewPort.
   virtual void InitAsPopup(content::RenderWidgetHostView* parent_host_view,
                            const gfx::Rect& pos) OVERRIDE;
   virtual void InitAsFullscreen(
       content::RenderWidgetHostView* reference_host_view) OVERRIDE;
   virtual void DidBecomeSelected() OVERRIDE;
   virtual void WasHidden() OVERRIDE;
   virtual void MovePluginWindows(
       const std::vector<webkit::npapi::WebPluginGeometry>& moves) OVERRIDE;
@@ skipping 199 matching lines @@
   // hidden until the software backing store has been updated. This variable is
   // set when the gpu widget needs to be hidden once a paint is completed.
   bool needs_gpu_visibility_update_after_repaint_;
 
   gfx::PluginWindowHandle compositing_surface_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_