Implement EXT_draw_buffers WebGL extention support in command buffer.

webkit/gpu/webgraphicscontext3d_in_process_command_buffer_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 WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_
 #define WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_
 
 #if defined(ENABLE_GPU)
 
 #include <vector>
@@ skipping 485 matching lines @@
   virtual void consumeTextureCHROMIUM(WGC3Denum target,
                                       const WGC3Dbyte* mailbox);
 
   virtual void insertEventMarkerEXT(const WGC3Dchar* marker);
   virtual void pushGroupMarkerEXT(const WGC3Dchar* marker);
   virtual void popGroupMarkerEXT();
 
   virtual void* mapBufferCHROMIUM(WGC3Denum target, WGC3Denum access);
   virtual WGC3Dboolean unmapBufferCHROMIUM(WGC3Denum target);
 
+  virtual void drawBuffersEXT(WGC3Dsizei n, const WGC3Denum* bufs);
+
  protected:
   virtual GrGLInterface* onCreateGrGLInterface();
 
  private:
   // SwapBuffers callback.
   void OnSwapBuffersComplete();
   virtual void OnContextLost();
 
   // Used to try to find bugs in code that calls gl directly through the gl api
   // instead of going through WebGraphicsContext3D.
@@ skipping 22 matching lines @@
                       unsigned int width,
                       unsigned int height);
 #endif
 };
 
 }  // namespace gpu
 }  // namespace webkit
 
 #endif  // defined(ENABLE_GPU)
 #endif  // WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_COMMAND_BUFFER_IMPL_H_