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

chrome/browser/media/router/presentation_service_delegate_impl.cc

Index: chrome/browser/media/router/presentation_service_delegate_impl.cc
diff --git a/chrome/browser/media/router/presentation_service_delegate_impl.cc b/chrome/browser/media/router/presentation_service_delegate_impl.cc
index 2cd8f5054c9af2c1cc13e1c7fec1623d186e01a7..4c5a12c69468b63b374f14309aaa479562eb4e4f 100644
--- a/chrome/browser/media/router/presentation_service_delegate_impl.cc
+++ b/chrome/browser/media/router/presentation_service_delegate_impl.cc
@@ -213,6 +213,7 @@ void PresentationFrame::OnPresentationSessionStarted(
     const MediaRoute& route) {
   presentation_id_to_route_.insert(
       std::make_pair(session.presentation_id, route));
+  router_->RegisterPresentationRoute(session.presentation_id, route);
 }
 
 const MediaRoute::Id PresentationFrame::GetRouteId(
@@ -270,6 +271,7 @@ void PresentationFrame::Reset() {
           pid_route.first, render_frame_host_id_);
     }
     router_->DetachRoute(pid_route.second.media_route_id());
+    router_->UnregisterPresentationRoute(pid_route.first);
   }
 
   presentation_id_to_route_.clear();
@@ -284,6 +286,8 @@ void PresentationFrame::RemoveConnection(const std::string& presentation_id,
   // Remove the presentation id mapping so a later call to Reset is a no-op.
   presentation_id_to_route_.erase(presentation_id);
 
+  router_->UnregisterPresentationRoute(presentation_id);
+
   // We no longer need to observe route messages.
   session_messages_observers_.erase(route_id);