Add WebGraphicsContext support for readbacks from any framebuffer.

webkit/gpu/webgraphicscontext3d_in_process_impl.h

 // Copyright (c) 2011 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 WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_
 #define WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_
 
 #include <list>
 #include <set>
 
@@ skipping 52 matching lines @@
   virtual int width();
   virtual int height();
 
   virtual bool isGLES2Compliant();
 
   virtual bool setParentContext(WebGraphicsContext3D* parent_context);
 
   virtual void reshape(int width, int height);
 
   virtual bool readBackFramebuffer(unsigned char* pixels, size_t bufferSize);
+  virtual bool readBackFramebuffer(unsigned char* pixels, size_t buffer_size,
+                                   WebGLId framebuffer, int width, int height);
 
   virtual WebGLId getPlatformTextureId();
   virtual void prepareTexture();
 
   virtual void synthesizeGLError(WGC3Denum error);
   virtual void* mapBufferSubDataCHROMIUM(WGC3Denum target, WGC3Dintptr offset,
                                          WGC3Dsizeiptr size, WGC3Denum access);
   virtual void unmapBufferSubDataCHROMIUM(const void*);
   virtual void* mapTexSubImage2DCHROMIUM(
       WGC3Denum target,
@@ skipping 393 matching lines @@
   ShaderSourceMap shader_source_map_;
 
   ShHandle fragment_compiler_;
   ShHandle vertex_compiler_;
 };
 
 }  // namespace gpu
 }  // namespace webkit
 
 #endif  // WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_