[Media Router] Add a presentation id to MediaRoute mapping in the MR

chrome/browser/media/router/presentation_service_delegate_impl.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_service_delegate_impl.h"
 
 #include <string>
 #include <unordered_map>
 #include <utility>
 #include <vector>
@@ skipping 189 matching lines @@
 }
 
 PresentationFrame::~PresentationFrame() {
 }
 
 void PresentationFrame::OnPresentationSessionStarted(
     const content::PresentationSessionInfo& session,
     const MediaRoute& route) {
   presentation_id_to_route_.insert(
       std::make_pair(session.presentation_id, route));
+  router_->SetPresentationId(route.media_route_id(), session.presentation_id);
 }
 
 const MediaRoute::Id PresentationFrame::GetRouteId(
     const std::string& presentation_id) const {
   auto it = presentation_id_to_route_.find(presentation_id);
   return it != presentation_id_to_route_.end() ? it->second.media_route_id()
                                                : "";
 }
 
 bool PresentationFrame::SetScreenAvailabilityListener(
@@ skipping 831 matching lines @@
   const base::ListValue* origins =
       Profile::FromBrowserContext(web_contents_->GetBrowserContext())
           ->GetPrefs()
           ->GetList(prefs::kMediaRouterTabMirroringSources);
   return origins &&
          origins->Find(base::Value(origin.Serialize())) != origins->end();
 }
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace media_router