[Media Router] Support dual discovery

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

Index: chrome/browser/media/router/discovery/media_sink_service_base.cc
diff --git a/chrome/browser/media/router/discovery/media_sink_service_base.cc b/chrome/browser/media/router/discovery/media_sink_service_base.cc
index a1ccff11dccc786dfa4f97ed3ef1417eae112fb2..7e382a2a35994a956fa7bb828b246c84786680a6 100644
--- a/chrome/browser/media/router/discovery/media_sink_service_base.cc
+++ b/chrome/browser/media/router/discovery/media_sink_service_base.cc
@@ -20,6 +20,15 @@ MediaSinkServiceBase::MediaSinkServiceBase(
 
 MediaSinkServiceBase::~MediaSinkServiceBase() = default;
 
+void MediaSinkServiceBase::AddObserver(Observer* observer) {
+  if (!observers_.HasObserver(observer))
+    observers_.AddObserver(observer);
+}
+
+void MediaSinkServiceBase::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void MediaSinkServiceBase::SetTimerForTest(std::unique_ptr<base::Timer> timer) {
   DCHECK(!finish_timer_);
   finish_timer_ = std::move(timer);
@@ -63,4 +72,22 @@ void MediaSinkServiceBase::RestartTimer() {
   StartTimer();
 }
 
+void MediaSinkServiceBase::AddSink(const MediaSinkInternal& sink) {
+  if (!current_sinks_.insert(sink).second)
+    return;
+
+  for (auto& observer : observers_)
+    observer.OnMediaSinkAdded(sink);
+}
+
+void MediaSinkServiceBase::RemoveSinks() {
+  current_sinks_.clear();
+  for (auto& observer : observers_)
+    observer.OnMediaSinksRemoved();
+}
+
+size_t MediaSinkServiceBase::GetCurrentSinksSize() {
+  return current_sinks_.size();
+}
+
 }  // namespace media_router