Cleanup of the metro viewer code

win8/metro_driver/chrome_app_view_ash.h

 // 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.
 
 #ifndef WIN8_METRO_DRIVER_CHROME_APP_VIEW_ASH_H_
 #define WIN8_METRO_DRIVER_CHROME_APP_VIEW_ASH_H_
 
 #include <windows.applicationmodel.core.h>
 #include <windows.ui.core.h>
 #include <windows.ui.input.h>
@@ skipping 96 matching lines @@
   EventRegistrationToken keyup_token_;
   EventRegistrationToken character_received_token_;
   EventRegistrationToken visibility_changed_token_;
   EventRegistrationToken accel_keydown_token_;
   EventRegistrationToken accel_keyup_token_;
 
   // Keep state about which button is currently down, if any, as PointerMoved
   // events do not contain that state, but Ash's MouseEvents need it.
   ui::EventFlags mouse_down_flags_;
 
+  // Set the D3D swap chain and nothing else.
   metro_driver::Direct3DHelper direct3d_helper_;
 
+  // The channel to Chrome, in particular to the MetroViewerProcessHost.
   IPC::ChannelProxy* ui_channel_;
+
+  // The actual window behind the view surface.
+  HWND core_window_hwnd_;
 };
 
 #endif  // WIN8_METRO_DRIVER_CHROME_APP_VIEW_ASH_H_