Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

chrome/browser/media/router/media_router_base.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_router_base.h"
 
 #include "base/bind.h"
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace media_router {
 
 // A MediaRoutesObserver that maintains state about the current set of media
 // routes.
 class MediaRouterBase::InternalMediaRoutesObserver
     : public MediaRoutesObserver {
  public:
   explicit InternalMediaRoutesObserver(MediaRouter* router)
       : MediaRoutesObserver(router), has_route(false) {}
   ~InternalMediaRoutesObserver() override {}
 
   // MediaRoutesObserver
   void OnRoutesUpdated(
       const std::vector<MediaRoute>& routes,
       const std::vector<MediaRoute::Id>& joinable_route_ids) override {
+    current_routes = routes;
     incognito_route_ids.clear();
     // TODO(crbug.com/611486): Have the MRPM pass a list of joinable route ids
     // via |joinable_route_ids|, and check here if it is non-empty.
     has_route = !routes.empty();
     for (const auto& route : routes) {
       if (route.is_incognito())
         incognito_route_ids.push_back(route.media_route_id());
     }
   }
 
   bool has_route;
+  std::vector<MediaRoute> current_routes;
   std::vector<MediaRoute::Id> incognito_route_ids;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InternalMediaRoutesObserver);
 };
 
 MediaRouterBase::~MediaRouterBase() {
   CHECK(!internal_routes_observer_);
 }
 
@@ skipping 14 matching lines @@
   }
 
   return callbacks->Add(callback);
 }
 
 void MediaRouterBase::OnIncognitoProfileShutdown() {
   for (const auto& route_id : internal_routes_observer_->incognito_route_ids)
     TerminateRoute(route_id);
 }
 
+std::vector<MediaRoute> MediaRouterBase::GetCurrentRoutes() const {
+  return internal_routes_observer_->current_routes;
+}
+
 MediaRouterBase::MediaRouterBase() : initialized_(false) {}
 
 // static
 std::string MediaRouterBase::CreatePresentationId() {
   return "mr_" + base::GenerateGUID();
 }
 
 void MediaRouterBase::NotifyPresentationConnectionStateChange(
     const MediaRoute::Id& route_id,
     content::PresentationConnectionState state) {
@@ skipping 41 matching lines @@
     presentation_connection_state_callbacks_.erase(route_id);
 }
 
 void MediaRouterBase::Shutdown() {
   // The observer calls virtual methods on MediaRouter; it must be destroyed
   // outside of the dtor
   internal_routes_observer_.reset();
 }
 
 }  // namespace media_router