Use C OpenGL interface in mojo::GLContext

mojo/public/platform/native/gles2_impl_chromium_sub_image_thunks.h

-// Copyright 2015 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 MOJO_PUBLIC_PLATFORM_NATIVE_GLES2_IMPL_CHROMIUM_SUB_IMAGE_THUNKS_H_
-#define MOJO_PUBLIC_PLATFORM_NATIVE_GLES2_IMPL_CHROMIUM_SUB_IMAGE_THUNKS_H_
-
-#include <stddef.h>
-
-#include "mojo/public/c/gles2/chromium_sub_image.h"
-
-// Specifies the frozen API for the GLES2 CHROMIUM_sub_image extension.
-#pragma pack(push, 8)
-struct MojoGLES2ImplChromiumSubImageThunks {
-  size_t size;  // Should be set to sizeof(*this).
-
-#define VISIT_GL_CALL(Function, ReturnType, PARAMETERS, ARGUMENTS) \
-  ReturnType(GL_APIENTRY *Function) PARAMETERS;
-#include "mojo/public/c/gles2/gles2_call_visitor_chromium_sub_image_autogen.h"
-#undef VISIT_GL_CALL
-};
-#pragma pack(pop)
-
-// Intended to be called from the embedder to get the embedder's implementation
-// of GLES2.
-inline MojoGLES2ImplChromiumSubImageThunks
-MojoMakeGLES2ImplChromiumSubImageThunks() {
-  MojoGLES2ImplChromiumSubImageThunks gles2_impl_chromium_sub_image_thunks = {
-      sizeof(MojoGLES2ImplChromiumSubImageThunks),
-#define VISIT_GL_CALL(Function, ReturnType, PARAMETERS, ARGUMENTS) gl##Function,
-#include "mojo/public/c/gles2/gles2_call_visitor_chromium_sub_image_autogen.h"
-#undef VISIT_GL_CALL
-  };
-
-  return gles2_impl_chromium_sub_image_thunks;
-}
-
-// Use this type for the function found by dynamically discovering it in
-// a DSO linked with mojo_system.
-// The contents of |gles2_impl_chromium_sub_image_thunks| are copied.
-typedef size_t (*MojoSetGLES2ImplChromiumSubImageThunksFn)(
-    const MojoGLES2ImplChromiumSubImageThunks* thunks);
-
-#endif  // MOJO_PUBLIC_PLATFORM_NATIVE_GLES2_IMPL_CHROMIUM_SUB_IMAGE_THUNKS_H_