[Media Router] Implement JoinRoute + update CreateRoute API.

chrome/browser/ui/webui/media_router/media_router_ui.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_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 80 matching lines @@
   // Calls MediaRouter to close the given route.
   void CloseRoute(const MediaRoute::Id& route_id);
 
   // Calls MediaRouter to clear the given issue.
   void ClearIssue(const Issue::Id& issue_id);
 
   // Returns the header text that should be displayed in the UI when it is
   // initially loaded. The header text is determined by the preferred cast mode.
   std::string GetInitialHeaderText() const;
 
+  // Returns the hostname of the default source's parent frame URL.
+  std::string GetFrameURLHost() const;
   bool has_pending_route_request() const { return has_pending_route_request_; }
   const GURL& frame_url() const { return frame_url_; }
   const std::vector<MediaSinkWithCastModes>& sinks() const { return sinks_; }
   const std::vector<MediaRoute>& routes() const { return routes_; }
   const std::set<MediaCastMode>& cast_modes() const { return cast_modes_; }
 
   const content::WebContents* initiator() const { return initiator_; }
 
  private:
   class UIIssuesObserver;
@@ skipping 82 matching lines @@
   // NOTE: Weak pointers must be invalidated before all other member variables.
   // Therefore |weak_factory_| must be placed at the end.
   base::WeakPtrFactory<MediaRouterUI> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterUI);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_