[Media Router] Implement JoinRoute + update CreateRoute API.

chrome/browser/media/router/presentation_service_delegate_impl.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_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 100 matching lines @@
 
   // Observer interface for listening to default MediaSource changes for the
   // WebContents.
   class DefaultMediaSourceObserver {
    public:
     virtual ~DefaultMediaSourceObserver() {}
 
     // Called when default media source for the corresponding WebContents has
     // changed.
     // |source|: New default MediaSource, or empty if default was removed.
-    // |frame_url|: URL of the frame that contains the default
-    //     media source, or empty if there is no default media source.
-    virtual void OnDefaultMediaSourceChanged(
-        const MediaSource& source,
-        const GURL& frame_url) = 0;
+    // |frame_url|: URL of the frame that contains the default media
+    //     source, or empty if there is no default media source.
+    virtual void OnDefaultMediaSourceChanged(const MediaSource& source,
+                                             const GURL& frame_url) = 0;
   };
 
   // Adds / removes an observer for listening to default MediaSource changes.
   void AddDefaultMediaSourceObserver(DefaultMediaSourceObserver* observer);
   void RemoveDefaultMediaSourceObserver(DefaultMediaSourceObserver* observer);
 
   void SetMediaRouterForTest(MediaRouter* router);
   bool HasScreenAvailabilityListenerForTest(
       int render_process_id,
       int render_frame_id,
       const MediaSource::Id& source_id) const;
 
   base::WeakPtr<PresentationServiceDelegateImpl> GetWeakPtr();
 
  private:
   explicit PresentationServiceDelegateImpl(content::WebContents* web_contents);
   friend class content::WebContentsUserData<PresentationServiceDelegateImpl>;
 
   FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplTest,
                            DelegateObservers);
 
   // Returns |listener|'s presentation URL as a MediaSource. If |listener| does
   // not have a persentation URL, returns the tab mirroring MediaSource.
   MediaSource GetMediaSourceFromListener(
       content::PresentationScreenAvailabilityListener* listener);
 
   // Returns |true| if the frame is the main frame of |web_contents_|.
   bool IsMainFrame(int render_process_id, int render_frame_id) const;
 
-  // Updates tab-level default MediaSource and source host name. If either
+  // Updates tab-level default MediaSource and/or default frame URL. If either
   // changed, notify the observers.
   void UpdateDefaultMediaSourceAndNotifyObservers(
       const MediaSource& new_default_source,
       const GURL& new_default_frame_url);
 
+  // Default MediaSource for the tab associated with this instance.
   MediaSource default_source_;
+  // URL of the frame that contains the default MediaSource.
   GURL default_frame_url_;
 
   // References to the observers listening for changes to default media source.
   base::ObserverList<
       DefaultMediaSourceObserver> default_media_source_observers_;
 
   // References to the WebContents that owns this instance, and associated
   // browser profile's MediaRouter instance.
   content::WebContents* web_contents_;
   MediaRouter* router_;
 
   scoped_ptr<PresentationFrameManager> frame_manager_;
 
   base::WeakPtrFactory<PresentationServiceDelegateImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PresentationServiceDelegateImpl);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_