Add common GLFence::IsSupported() check

gpu/command_buffer/service/mailbox_synchronizer.cc

 // Copyright 2014 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 "gpu/command_buffer/service/mailbox_synchronizer.h"
 
 #include "base/bind.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
 #include "gpu/command_buffer/service/texture_manager.h"
+#include "ui/gl/gl_fence.h"
 #include "ui/gl/gl_implementation.h"
 
 namespace gpu {
 namespace gles2 {
 
 namespace {
 
 MailboxSynchronizer* g_instance = NULL;
 
 }  // anonymous namespace
 
 // static
 bool MailboxSynchronizer::Initialize() {
   DCHECK(!g_instance);
   DCHECK(gfx::GetGLImplementation() != gfx::kGLImplementationNone)
       << "GL bindings not initialized";
   switch (gfx::GetGLImplementation()) {
     case gfx::kGLImplementationMockGL:
       break;
     case gfx::kGLImplementationEGLGLES2:
 #if !defined(OS_MACOSX)
       {
         if (!gfx::g_driver_egl.ext.b_EGL_KHR_image_base ||
             !gfx::g_driver_egl.ext.b_EGL_KHR_gl_texture_2D_image ||
             !gfx::g_driver_gl.ext.b_GL_OES_EGL_image ||
-            !gfx::g_driver_egl.ext.b_EGL_KHR_fence_sync) {
+            !gfx::GLFence::IsSupported()) {
           LOG(WARNING) << "MailboxSync not supported due to missing EGL "
                           "image/fence support";
           return false;
         }
       }
       break;
 #endif
     default:
       NOTREACHED();
       return false;
@@ skipping 171 matching lines @@
           definition.IsOlderThan(it->second.version))
         continue;
       it->second.version = definition.version();
       definition.UpdateTexture(texture);
     }
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu