[MediaRouter] Update JoinRoute behavior to allow non-local routes.

chrome/browser/media/router/media_router_base.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_MEDIA_ROUTER_MEDIA_ROUTER_BASE_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_BASE_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 34 matching lines @@
   static std::string CreatePresentationId();
 
   void NotifyPresentationConnectionStateChange(
       const MediaRoute::Id& route_id,
       content::PresentationConnectionState state);
   void NotifyPresentationConnectionClose(
       const MediaRoute::Id& route_id,
       content::PresentationConnectionCloseReason reason,
       const std::string& message);
 
-  // Returns true when there is at least one MediaRoute with is_local = true.
-  bool HasLocalRoute() const;
+  // Returns true when there is at least one MediaRoute that can be returned by
+  // JoinRoute().
+  bool HasJoinableRoute() const;
 
   using PresentationConnectionStateChangedCallbacks = base::CallbackList<void(
       const content::PresentationConnectionStateChangeInfo&)>;
 
   base::ScopedPtrHashMap<
       MediaRoute::Id,
       std::unique_ptr<PresentationConnectionStateChangedCallbacks>>
       presentation_connection_state_callbacks_;
 
   base::ThreadChecker thread_checker_;
@@ skipping 17 matching lines @@
 
   std::unique_ptr<InternalMediaRoutesObserver> internal_routes_observer_;
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterBase);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_BASE_H_