Introduce GLStubApi

ui/gl/gl_context_stub.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_context_stub.h"
 
+#include "ui/gl/gl_gl_api_implementation.h"
+
 namespace gl {
 
 GLContextStub::GLContextStub() : GLContextReal(nullptr) {}
 GLContextStub::GLContextStub(GLShareGroup* share_group)
     : GLContextReal(share_group) {}
 
 bool GLContextStub::Initialize(
     GLSurface* compatible_surface, GpuPreference gpu_preference) {
   return true;
 }
 
 bool GLContextStub::MakeCurrent(GLSurface* surface) {
-  SetRealGLApi();
+  SetGLToStubGLApi();
   SetCurrent(surface);
   InitializeDynamicBindings();
   return true;
 }
 
 void GLContextStub::ReleaseCurrent(GLSurface* surface) {
   SetCurrent(nullptr);
 }
 
 bool GLContextStub::IsCurrent(GLSurface* surface) {
   return GetRealCurrent() == this;
 }
 
 void* GLContextStub::GetHandle() {
   return nullptr;
 }
 
 void GLContextStub::OnSetSwapInterval(int interval) {
 }
 
 std::string GLContextStub::GetGLRenderer() {
   return std::string("CHROMIUM");
 }
 
 GLContextStub::~GLContextStub() {}
 
 }  // namespace gl