[Media Router] Support dual discovery

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

 // 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.
 #include "chrome/browser/media/router/discovery/media_sink_service_base.h"
 
 #include <vector>
 
 namespace {
 // Time interval when media sink service sends sinks to MRP.
 const int kFetchCompleteTimeoutSecs = 3;
 }
 
 namespace media_router {
 
 MediaSinkServiceBase::MediaSinkServiceBase(
     const OnSinksDiscoveredCallback& callback)
     : MediaSinkService(callback) {
   fetch_complete_timeout_secs_ = kFetchCompleteTimeoutSecs;
 }
 
 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);
 }
 
 void MediaSinkServiceBase::OnFetchCompleted() {
   DCHECK(!sink_discovery_callback_.is_null());
 
   if (current_sinks_ == mrp_sinks_) {
     DVLOG(2) << "No update to sink list.";
@@ skipping 23 matching lines @@
 void MediaSinkServiceBase::StopTimer() {
   finish_timer_.reset();
 }
 
 void MediaSinkServiceBase::RestartTimer() {
   if (!finish_timer_ || finish_timer_->IsRunning())
     return;
   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