Plumb through EGL_NV_post_sub_buffer and GLX_MESA_copy_sub_buffer.

gpu/command_buffer/client/gles2_c_lib_autogen.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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // DO NOT EDIT!
 
 // These functions emluate GLES2 over command buffers.
 #ifndef GPU_COMMAND_BUFFER_CLIENT_GLES2_C_LIB_AUTOGEN_H_
@@ skipping 568 matching lines @@
   return gles2::GetGLContext()->CreateStreamTextureCHROMIUM(texture);
 }
 void GLES2DestroyStreamTextureCHROMIUM(GLuint texture) {
   gles2::GetGLContext()->DestroyStreamTextureCHROMIUM(texture);
 }
 void GLES2GetTranslatedShaderSourceANGLE(
     GLuint shader, GLsizei bufsize, GLsizei* length, char* source) {
   gles2::GetGLContext()->GetTranslatedShaderSourceANGLE(
       shader, bufsize, length, source);
 }
+void GLES2PostSubBufferCHROMIUM(GLint x, GLint y, GLint width, GLint height) {
+  gles2::GetGLContext()->PostSubBufferCHROMIUM(x, y, width, height);
+}
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_C_LIB_AUTOGEN_H_