Implement EXT_draw_buffers WebGL extention support in command buffer.

gpu/command_buffer/client/gles2_c_lib_autogen.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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // DO NOT EDIT!
 
 // These functions emulate GLES2 over command buffers.
 #ifndef GPU_COMMAND_BUFFER_CLIENT_GLES2_C_LIB_AUTOGEN_H_
@@ skipping 710 matching lines @@
 }
 void GLES2LoseContextCHROMIUM(GLenum current, GLenum other) {
   gles2::GetGLContext()->LoseContextCHROMIUM(current, other);
 }
 GLuint GLES2InsertSyncPointCHROMIUM() {
   return gles2::GetGLContext()->InsertSyncPointCHROMIUM();
 }
 void GLES2WaitSyncPointCHROMIUM(GLuint sync_point) {
   gles2::GetGLContext()->WaitSyncPointCHROMIUM(sync_point);
 }
+void GLES2DrawBuffersEXT(GLsizei count, const GLenum* bufs) {
+  gles2::GetGLContext()->DrawBuffersEXT(count, bufs);
+}
 
 namespace gles2 {
 
 NameToFunc g_gles2_function_table[] = {
   { "glActiveTexture", reinterpret_cast<GLES2FunctionPointer>(
       glActiveTexture), },
   { "glAttachShader", reinterpret_cast<GLES2FunctionPointer>(
       glAttachShader), },
   { "glBindAttribLocation", reinterpret_cast<GLES2FunctionPointer>(
       glBindAttribLocation), },
@@ skipping 321 matching lines @@
   { "glWaitAsyncTexImage2DCHROMIUM", reinterpret_cast<GLES2FunctionPointer>(
       glWaitAsyncTexImage2DCHROMIUM), },
   { "glDiscardFramebufferEXT", reinterpret_cast<GLES2FunctionPointer>(
       glDiscardFramebufferEXT), },
   { "glLoseContextCHROMIUM", reinterpret_cast<GLES2FunctionPointer>(
       glLoseContextCHROMIUM), },
   { "glInsertSyncPointCHROMIUM", reinterpret_cast<GLES2FunctionPointer>(
       glInsertSyncPointCHROMIUM), },
   { "glWaitSyncPointCHROMIUM", reinterpret_cast<GLES2FunctionPointer>(
       glWaitSyncPointCHROMIUM), },
+  { "glDrawBuffersEXT", reinterpret_cast<GLES2FunctionPointer>(
+      glDrawBuffersEXT), },
   { NULL, NULL, },
 };
 
 }  // namespace gles2
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_C_LIB_AUTOGEN_H_