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

chrome/browser/media/router/presentation_request.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/presentation_request.h"
 
 #include "chrome/browser/media/router/media_source_helper.h"
 
 namespace media_router {
 
 PresentationRequest::PresentationRequest(
     const RenderFrameHostId& render_frame_host_id,
     const std::string& presentation_url,
     const GURL& frame_url)
     : render_frame_host_id_(render_frame_host_id),
       presentation_url_(presentation_url),
       frame_url_(frame_url) {}
 
+PresentationRequest::PresentationRequest(const PresentationRequest& other) =
+    default;
+
 PresentationRequest::~PresentationRequest() = default;
 
 bool PresentationRequest::Equals(const PresentationRequest& other) const {
   return render_frame_host_id_ == other.render_frame_host_id_ &&
          presentation_url_ == other.presentation_url_ &&
          frame_url_ == other.frame_url_;
 }
 
 MediaSource PresentationRequest::GetMediaSource() const {
   return MediaSourceForPresentationUrl(presentation_url_);
 }
 
 }  // namespace media_router