GLContext no longer holds a pointer to a GLSurface.

ui/gfx/gl/gl_surface_win.cc

 // Copyright (c) 2011 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/gfx/gl/gl_surface.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "third_party/mesa/MesaLib/include/GL/osmesa.h"
 #include "ui/gfx/gl/gl_bindings.h"
@@ skipping 87 matching lines @@
 
   device_context_ = GetDC(window_);
   UpdateSize();
   return true;
 }
 
 void NativeViewGLSurfaceOSMesa::Destroy() {
   if (window_ && device_context_)
     ReleaseDC(window_, device_context_);
 
-  window_ = NULL;
   device_context_ = NULL;
 
   GLSurfaceOSMesa::Destroy();
 }
 
 bool NativeViewGLSurfaceOSMesa::IsOffscreen() {
   return false;
 }
 
 bool NativeViewGLSurfaceOSMesa::SwapBuffers() {
@@ skipping 108 matching lines @@
     }
     case kGLImplementationMockGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 }  // namespace gfx