Refactor GL bindings so there is no global GLApi or DriverGL.

gpu/ipc/service/image_transport_surface_overlay_mac.h

 // Copyright 2015 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.
 
 #ifndef GPU_IPC_SERVICE_IMAGE_TRANSPORT_SURFACE_OVERLAY_MAC_H_
 #define GPU_IPC_SERVICE_IMAGE_TRANSPORT_SURFACE_OVERLAY_MAC_H_
 
 #include <list>
 #include <memory>
 #include <vector>
@@ skipping 74 matching lines @@
   base::scoped_nsobject<CAContext> ca_context_;
   base::scoped_nsobject<CAContext> fullscreen_low_power_ca_context_;
   std::unique_ptr<ui::CALayerTreeCoordinator> ca_layer_tree_coordinator_;
 
   gfx::Size pixel_size_;
   float scale_factor_;
 
   std::vector<CALayerInUseQuery> ca_layer_in_use_queries_;
 
   // A GLFence marking the end of the previous frame. Must only be accessed
-  // while in a ScopedSetGLToRealGLApi, and while the associated
-  // |previous_frame_context_| is bound.
+  // while the associated |previous_frame_context_| is bound.
   std::unique_ptr<gl::GLFence> previous_frame_fence_;
   base::ScopedTypeRef<CGLContextObj> fence_context_obj_;
 
   // The renderer ID that all contexts made current to this surface should be
   // targeting.
   GLint gl_renderer_id_;
 };
 
 }  // namespace gpu
 
 #endif  // GPU_IPC_SERVICE_IMAGE_TRANSPORT_SURFACE_OVERLAY_MAC_H_