Add GL_CHROMIUM_get_error_query

gpu/command_buffer/client/gles2_implementation.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 GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 180 matching lines @@
 
   ~GLES2Implementation();
 
   bool Initialize(
       unsigned int starting_transfer_buffer_size,
       unsigned int min_transfer_buffer_size,
       unsigned int max_transfer_buffer_size);
 
   // The GLES2CmdHelper being used by this GLES2Implementation. You can use
   // this to issue cmds at a lower level for certain kinds of optimization.
-  GLES2CmdHelper* helper() const {
-    return helper_;
-  }
+  GLES2CmdHelper* helper() const;
+
+  // Gets client side generated errors.
+  GLenum GetClientSideGLError();
 
   // Include the auto-generated part of this class. We split this because
   // it means we can easily edit the non-auto generated parts right here in
   // this file instead of having to edit some template or the code generator.
   #include "../client/gles2_implementation_autogen.h"
 
   void DisableVertexAttribArray(GLuint index);
   void EnableVertexAttribArray(GLuint index);
   void GetVertexAttribfv(GLuint index, GLenum pname, GLfloat* params);
   void GetVertexAttribiv(GLuint index, GLenum pname, GLint* params);
@@ skipping 385 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_