This CL adds client.toDataURL which gets the contents...

core/win/d3d9/renderer_d3d9.h

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 138 matching lines @@
 
   // Creates and returns a D3D9 specific Sampler object.
   virtual Sampler::Ref CreateSampler();
 
   // Creates and returns a platform-specific RenderDepthStencilSurface object
   // for use as a depth-stencil render target.
   virtual RenderDepthStencilSurface::Ref CreateDepthStencilSurface(
       int width,
       int height);
 
-  // Saves a png screenshot 'file_name.png'.
-  // Returns true on success and false on failure.
-  virtual bool SaveScreen(const String& file_name);
+  // Overridden from Renderer.
+  virtual Bitmap::Ref TakeScreenshot();
 
   inline LPDIRECT3DDEVICE9 d3d_device() const { return d3d_device_; }
   inline LPDIRECT3D9 d3d() const { return d3d_; }
 
   inline DWORD supported_depth_format() const {
     return supported_depth_format_;
   }
 
   // Overridden from Renderer.
   virtual const int* GetRGBAUByteNSwizzleTable();
@@ skipping 100 matching lines @@
 
   // The font to use to display the message when we go to fullscreen.
   CComPtr<ID3DXFont> fullscreen_message_font_;
   // The line used to draw the background for the message.
   CComPtr<ID3DXLine> fullscreen_message_line_;
 };
 
 }  // namespace o3d
 
 #endif  // O3D_CORE_WIN_D3D9_RENDERER_D3D9_H_