Maintain minimal error response.

content/browser/frame_host/render_widget_host_view_child_frame.h

 // Copyright 2014 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_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/common/content_export.h"
@@ skipping 62 matching lines @@
       const std::vector<gfx::Rect>& character_bounds) override;
   void RenderProcessGone(base::TerminationStatus status,
                          int error_code) override;
   void Destroy() override;
   void SetTooltipText(const base::string16& tooltip_text) override;
   void SelectionChanged(const base::string16& text,
                         size_t offset,
                         const gfx::Range& range) override;
   void SelectionBoundsChanged(
       const ViewHostMsg_SelectionBounds_Params& params) override;
-  void CopyFromCompositingSurface(const gfx::Rect& src_subrect,
-                                  const gfx::Size& dst_size,
-                                  ReadbackRequestCallback& callback,
-                                  const SkColorType color_type) override;
+  void CopyFromCompositingSurface(
+      const gfx::Rect& src_subrect,
+      const gfx::Size& dst_size,
+      ReadbackRequestCallback& callback,
+      const SkColorType preferred_color_type) override;
   void CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) override;
   bool CanCopyToVideoFrame() const override;
   bool HasAcceleratedSurface(const gfx::Size& desired_size) override;
   void OnSwapCompositorFrame(uint32 output_surface_id,
                              scoped_ptr<cc::CompositorFrame> frame) override;
   void GetScreenInfo(blink::WebScreenInfo* results) override;
   gfx::Rect GetBoundsInRootWindow() override;
@@ skipping 28 matching lines @@
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_WIN)
   void SetParentNativeViewAccessible(
       gfx::NativeViewAccessible accessible_parent) override;
   gfx::NativeViewId GetParentForWindowlessPlugin() const override;
 #endif
   BrowserAccessibilityManager* CreateBrowserAccessibilityManager(
       BrowserAccessibilityDelegate* delegate) override;
 
-  SkColorType PreferredReadbackFormat() override;
-
  protected:
   friend class RenderWidgetHostView;
 
   // The last scroll offset of the view.
   gfx::Vector2dF last_scroll_offset_;
 
   // Members will become private when RenderWidgetHostViewGuest is removed.
   // The model object.
   RenderWidgetHostImpl* host_;
 
   // frame_connector_ provides a platform abstraction. Messages
   // sent through it are routed to the embedding renderer process.
   CrossProcessFrameConnector* frame_connector_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewChildFrame);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_