media: Add out-of-line copy ctors for complex classes.

media/cdm/player_tracker_impl.h

 // 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.
 
 #ifndef MEDIA_CDM_PLAYER_TRACKER_IMPL_H_
 #define MEDIA_CDM_PLAYER_TRACKER_IMPL_H_
 
 #include <map>
 
 #include "base/callback.h"
@@ skipping 17 matching lines @@
   void UnregisterPlayer(int registration_id) override;
 
   // Helpers methods to fire registered callbacks.
   void NotifyNewKey();
   void NotifyCdmUnset();
 
  private:
   struct PlayerCallbacks {
     PlayerCallbacks(const base::Closure& new_key_cb,
                     const base::Closure& cdm_unset_cb);
+    PlayerCallbacks(const PlayerCallbacks& other);
     ~PlayerCallbacks();
 
     base::Closure new_key_cb;
     base::Closure cdm_unset_cb;
   };
 
   // Lock used to serialize access to other data members.
   base::Lock lock_;
 
   int next_registration_id_;
   std::map<int, PlayerCallbacks> player_callbacks_map_;
 
   DISALLOW_COPY_AND_ASSIGN(PlayerTrackerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CDM_PLAYER_TRACKER_IMPL_H_