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

chrome/browser/media/router/media_route.cc

 // 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.
 
 #include "chrome/browser/media/router/media_route.h"
 
 #include "base/logging.h"
 #include "chrome/browser/media/router/media_source.h"
 
 namespace media_router {
 
 MediaRoute::MediaRoute(const MediaRoute::Id& media_route_id,
                        const MediaSource& media_source,
                        const MediaSink::Id& media_sink_id,
                        const std::string& description,
                        bool is_local,
                        const std::string& custom_controller_path,
                        bool for_display)
     : media_route_id_(media_route_id),
       media_source_(media_source),
       media_sink_id_(media_sink_id),
       description_(description),
       is_local_(is_local),
       custom_controller_path_(custom_controller_path),
       for_display_(for_display) {}
 
+MediaRoute::MediaRoute(const MediaRoute& other) = default;
+
 MediaRoute::~MediaRoute() {
 }
 
 bool MediaRoute::Equals(const MediaRoute& other) const {
   return media_route_id_ == other.media_route_id_;
 }
 
 }  // namespace media_router