Implement "Save image as" for canvas (chromium side).

content/browser/renderer_host/render_view_host_impl.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_VIEW_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 139 matching lines @@
       bool swapped_out,
       bool hidden);
   virtual ~RenderViewHostImpl();
 
   // RenderViewHost implementation.
   virtual RenderFrameHost* GetMainFrame() OVERRIDE;
   virtual void AllowBindings(int binding_flags) OVERRIDE;
   virtual void ClearFocusedElement() OVERRIDE;
   virtual void ClosePage() OVERRIDE;
   virtual void CopyImageAt(int x, int y) OVERRIDE;
+  virtual void SaveImageAt(int x, int y) OVERRIDE;
   virtual void DirectoryEnumerationFinished(
       int request_id,
       const std::vector<base::FilePath>& files) OVERRIDE;
   virtual void DisableScrollbarsForThreshold(const gfx::Size& size) OVERRIDE;
   virtual void DragSourceEndedAt(
       int client_x, int client_y, int screen_x, int screen_y,
       blink::WebDragOperation operation) OVERRIDE;
   virtual void DragSourceSystemDragEnded() OVERRIDE;
   virtual void DragTargetDragEnter(
       const DropData& drop_data,
@@ skipping 481 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_