[Media Router] Support dual discovery

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

Index: chrome/browser/media/router/discovery/media_sink_service_base.h
diff --git a/chrome/browser/media/router/discovery/media_sink_service_base.h b/chrome/browser/media/router/discovery/media_sink_service_base.h
index 482189555147a0a770ce62281743be3f9ba7848d..ef3d2f66c050985f020c2f04085f841d0dda09ed 100644
--- a/chrome/browser/media/router/discovery/media_sink_service_base.h
+++ b/chrome/browser/media/router/discovery/media_sink_service_base.h
@@ -9,6 +9,7 @@
 #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"
@@ -20,11 +21,15 @@ class MediaSinkServiceBase : public MediaSinkService {
   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.
@@ -40,19 +45,31 @@ class MediaSinkServiceBase : public MediaSinkService {
   // 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_;
 
-  // 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_;
+  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_;
 
   // Timer for finishing fetching.
   std::unique_ptr<base::Timer> finish_timer_;