Re-land: ui: Add GLImage unit test framework.

ui/gl/gl_gl_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_gl_api_implementation.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 316 matching lines @@
 
 void SetGLApiToNoContext() {
   SetGLApi(g_no_context_gl);
 }
 
 const GLVersionInfo* GetGLVersionInfo() {
   return g_version_info;
 }
 
 void InitializeDynamicGLBindingsGL(GLContext* context) {
+  if (g_version_info)
+    return;
   g_real_gl->InitializeFilteredExtensions();
   g_driver_gl.InitializeCustomDynamicBindings(context);
   DCHECK(context && context->IsCurrent(NULL) && !g_version_info);
   g_version_info = new GLVersionInfo(
       context->GetGLVersion().c_str(),
       context->GetGLRenderer().c_str(),
       context->GetExtensions().c_str());
 }
 
 void InitializeDebugGLBindingsGL() {
@@ skipping 262 matching lines @@
 
 void VirtualGLApi::glFlushFn() {
   GLApiBase::glFlushFn();
 }
 
 void VirtualGLApi::glFinishFn() {
   GLApiBase::glFinishFn();
 }
 
 }  // namespace gfx