Make GL calls go through subclassable class.

ui/gl/gl_surface_egl.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_surface_egl.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "build/build_config.h"
@@ skipping 182 matching lines @@
     LOG(ERROR) << "Trying to create surface with invalid display.";
     return false;
   }
 
   static const EGLint egl_window_attributes_sub_buffer[] = {
     EGL_POST_SUB_BUFFER_SUPPORTED_NV, EGL_TRUE,
     EGL_NONE
   };
 
   // Create a surface for the native window.
-  surface_ = eglCreateWindowSurface(GetDisplay(),
-                                    GetConfig(),
-                                    window_,
-                                    gfx::g_EGL_NV_post_sub_buffer ?
-                                        egl_window_attributes_sub_buffer :
-                                        NULL);
+  surface_ = eglCreateWindowSurface(
+      GetDisplay(),
+      GetConfig(),
+      window_,
+      gfx::g_driver_egl.ext.b_EGL_NV_post_sub_buffer ?
+          egl_window_attributes_sub_buffer :
+          NULL);
 
   if (!surface_) {
     LOG(ERROR) << "eglCreateWindowSurface failed with error "
                << GetLastEGLErrorString();
     Destroy();
     return false;
   }
 
   EGLint surfaceVal;
   EGLBoolean retVal = eglQuerySurface(GetDisplay(),
@@ skipping 264 matching lines @@
 
 EGLSurface PbufferGLSurfaceEGL::GetHandle() {
   return surface_;
 }
 
 void* PbufferGLSurfaceEGL::GetShareHandle() {
 #if defined(OS_ANDROID)
   NOTREACHED();
   return NULL;
 #else
-  if (!g_EGL_ANGLE_query_surface_pointer)
+  if (!gfx::g_driver_egl.ext.b_EGL_ANGLE_query_surface_pointer)
     return NULL;
 
-  if (!g_EGL_ANGLE_surface_d3d_texture_2d_share_handle)
+  if (!gfx::g_driver_egl.ext.b_EGL_ANGLE_surface_d3d_texture_2d_share_handle)
     return NULL;
 
   void* handle;
   if (!eglQuerySurfacePointerANGLE(g_display,
                                    GetHandle(),
                                    EGL_D3D_TEXTURE_2D_SHARE_HANDLE_ANGLE,
                                    &handle)) {
     return NULL;
   }
 
   return handle;
 #endif
 }
 
 PbufferGLSurfaceEGL::~PbufferGLSurfaceEGL() {
   Destroy();
 }
 
 }  // namespace gfx