Refactor content client to include a single Request/CancelPermission method.

content/browser/media/midi_dispatcher_host.h

 // Copyright 2013 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 CONTENT_BROWSER_MEDIA_MIDI_DISPATCHER_HOST_H_
 #define CONTENT_BROWSER_MEDIA_MIDI_DISPATCHER_HOST_H_
 
 #include <vector>
 
 #include "base/callback_forward.h"
@@ skipping 28 matching lines @@
                                  bool is_allowed);
 
   struct PendingPermission {
     PendingPermission(int render_process_id,
                       int render_frame_id,
                       int bridge_id);
     ~PendingPermission();
     int render_process_id;
     int render_frame_id;
     int bridge_id;
-    base::Closure cancel;
   };
   std::vector<PendingPermission> pending_permissions_;
 
   base::WeakPtrFactory<MidiDispatcherHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MidiDispatcherHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_MIDI_DISPATCHER_HOST_H_