Query the preferred readback config in CopyFromBackingStore

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_
 
 #import <Cocoa/Cocoa.h>
 #include <list>
 #include <map>
@@ skipping 327 matching lines @@
       const blink::WebMouseWheelEvent& event) OVERRIDE;
 
   // IPC::Sender implementation.
   virtual bool Send(IPC::Message* message) OVERRIDE;
 
   // SoftwareFrameManagerClient implementation:
   virtual void SoftwareFrameWasFreed(
       uint32 output_surface_id, unsigned frame_id) OVERRIDE;
   virtual void ReleaseReferencesToSoftwareFrame() OVERRIDE;
 
+  virtual SkBitmap::Config PreferredReadbackFormat() OVERRIDE;
+
   // Forwards the mouse event to the renderer.
   void ForwardMouseEvent(const blink::WebMouseEvent& event);
 
   void KillSelf();
 
   void SetTextInputActive(bool active);
 
   // Sends completed plugin IME notification and text back to the renderer.
   void PluginImeCompositionCompleted(const base::string16& text, int plugin_id);
 
@@ skipping 287 matching lines @@
   scoped_ptr<RenderWidgetHostViewFrameSubscriber> frame_subscriber_;
 
   base::WeakPtrFactory<RenderWidgetHostViewMac>
       software_frame_weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_