implement getBufferSubDataAsync prototype

gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h

 // Copyright 2014 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
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 1118 matching lines @@
 void GLES2InterfaceStub::BindFragmentInputLocationCHROMIUM(
     GLuint /* program */,
     GLint /* location */,
     const char* /* name */) {}
 void GLES2InterfaceStub::ProgramPathFragmentInputGenCHROMIUM(
     GLuint /* program */,
     GLint /* location */,
     GLenum /* genMode */,
     GLint /* components */,
     const GLfloat* /* coeffs */) {}
+void* GLES2InterfaceStub::GetBufferSubDataAsyncCHROMIUM(GLenum /* target */,
+                                                        GLintptr /* offset */,
+                                                        GLsizeiptr /* size */) {
+  return 0;
+}
 void GLES2InterfaceStub::CoverageModulationCHROMIUM(GLenum /* components */) {}
 GLenum GLES2InterfaceStub::GetGraphicsResetStatusKHR() {
   return 0;
 }
 void GLES2InterfaceStub::BlendBarrierKHR() {}
 void GLES2InterfaceStub::ApplyScreenSpaceAntialiasingCHROMIUM() {}
 void GLES2InterfaceStub::BindFragDataLocationIndexedEXT(
     GLuint /* program */,
     GLuint /* colorNumber */,
     GLuint /* index */,
     const char* /* name */) {}
 void GLES2InterfaceStub::BindFragDataLocationEXT(GLuint /* program */,
                                                  GLuint /* colorNumber */,
                                                  const char* /* name */) {}
 GLint GLES2InterfaceStub::GetFragDataIndexEXT(GLuint /* program */,
                                               const char* /* name */) {
   return 0;
 }
 void GLES2InterfaceStub::UniformMatrix4fvStreamTextureMatrixCHROMIUM(
     GLint /* location */,
     GLboolean /* transpose */,
     const GLfloat* /* transform */) {}
 void GLES2InterfaceStub::SwapBuffersWithDamageCHROMIUM(GLint /* x */,
                                                        GLint /* y */,
                                                        GLint /* width */,
                                                        GLint /* height */) {}
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_INTERFACE_STUB_IMPL_AUTOGEN_H_