[Media Router] Support dual discovery

chrome/browser/media/router/discovery/media_sink_service_base.h

 // Copyright 2017 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_DISCOVERY_MEDIA_SINK_SERVICE_BASE_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MEDIA_SINK_SERVICE_BASE_H_
 
 #include <memory>
 #include <set>
 
 #include "base/gtest_prod_util.h"
+#include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "chrome/common/media_router/discovery/media_sink_internal.h"
 #include "chrome/common/media_router/discovery/media_sink_service.h"
 
 namespace media_router {
 
 class MediaSinkServiceBase : public MediaSinkService {
  public:
   explicit MediaSinkServiceBase(const OnSinksDiscoveredCallback& callback);
   ~MediaSinkServiceBase() override;
 
+  // MediaSinkService implementation
+  void AddObserver(Observer* observer) override;
+  void RemoveObserver(Observer* observer) override;
+
  protected:
   void SetTimerForTest(std::unique_ptr<base::Timer> timer);
 
   // Called when |finish_timer_| expires.
-  void OnFetchCompleted();
+  virtual void OnFetchCompleted();
 
   // Helper function to start |finish_timer_|. Create a new timer if none
   // exists.
   void StartTimer();
 
   // Helper function to stop |finish_timer_|.
   void StopTimer();
 
   // Helper function to restart |finish_timer|. No-op if timer does not exist or
   // timer is currently running.
   void RestartTimer();
 
   // Overriden by subclass to report device counts.
   virtual void RecordDeviceCounts() {}
 
+  // Adds media sink to current service.
+  void AddSink(const MediaSinkInternal& sink);
+
+  // Removes all media sinks from current service.
+  void RemoveSinks();
+
+  // Returns size of media sinks in current service.
+  size_t GetCurrentSinksSize();
+
   // Time out value for |finish_timer_|
   int fetch_complete_timeout_secs_;
 
+  base::ObserverList<MediaSinkService::Observer> observers_;
+
+ private:
+  friend class MediaSinkServiceBaseTest;
+  FRIEND_TEST_ALL_PREFIXES(MediaSinkServiceBaseTest,
+                           TestFetchCompleted_SameSink);
+  FRIEND_TEST_ALL_PREFIXES(MediaSinkServiceBaseTest, TestAddRemoveSinks);
+
   // Sorted sinks from current round of discovery.
   std::set<MediaSinkInternal> current_sinks_;
 
   // Sorted sinks sent to Media Router Provider in last FetchCompleted().
   std::set<MediaSinkInternal> mrp_sinks_;
 
- private:
-  friend class MediaSinkServiceBaseTest;
-  FRIEND_TEST_ALL_PREFIXES(MediaSinkServiceBaseTest,
-                           TestFetchCompleted_SameSink);
-
   // Timer for finishing fetching.
   std::unique_ptr<base::Timer> finish_timer_;
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_DISCOVERY_MEDIA_SINK_SERVICE_BASE_H_