Make GL calls go through subclassable class.

ui/gl/gl_egl_api_implementation.cc

+// 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.
+
+#include "ui/gl/gl_egl_api_implementation.h"
+
+namespace gfx {
+
+RealEGLApi g_real_egl;
+
+void InitializeGLBindingsEGL() {
+  g_driver_egl.InitializeBindings();
+  g_real_egl.Initialize(&g_driver_egl);
+  g_current_egl_context = &g_real_egl;
+}
+
+void InitializeGLExtensionBindingsEGL(GLContext* context) {
+  g_driver_osmesa.InitializeExtensionBindings(context);
+}
+
+void InitializeDebugGLBindingsEGL() {
+  g_driver_osmesa.InitializeDebugBindings();
+}
+
+void ClearGLBindingsEGL() {
+  g_driver_osmesa.ClearBindings();
+}
+
+EGLApi::EGLApi() {
+}
+
+EGLApi::~EGLApi() {
+}
+
+RealEGLApi::RealEGLApi() {
+}
+
+void RealEGLApi::Initialize(DriverEGL* driver) {
+  driver_ = driver;
+}
+
+}  // namespace gfx
+
+