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

chrome/browser/ui/webui/media_router/media_sink_with_cast_modes.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_SINK_WITH_CAST_MODES_H_
 #define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_SINK_WITH_CAST_MODES_H_
 
 #include <set>
 
 #include "chrome/browser/media/router/media_sink.h"
 #include "chrome/browser/ui/webui/media_router/media_cast_mode.h"
 
 namespace media_router {
 
 // Contains information on a MediaSink and the set of cast modes it is
 // compatible with. This should be interpreted under the context of a
 // QueryResultManager which contains a mapping from MediaCastMode to
 // MediaSource.
 struct MediaSinkWithCastModes {
   explicit MediaSinkWithCastModes(const MediaSink& sink);
+  MediaSinkWithCastModes(const MediaSinkWithCastModes& other);
   ~MediaSinkWithCastModes();
 
   MediaSink sink;
   CastModeSet cast_modes;
 
   bool Equals(const MediaSinkWithCastModes& other) const;
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_SINK_WITH_CAST_MODES_H_