[Presentation API] (3rd) (1-UA) Split PresentationServiceDelegateImpl(PSDImpl)

chrome/browser/media/router/presentation_service_delegate_observers.cc

+// Copyright 2016 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/presentation_service_delegate_observers.h"
+
+namespace media_router {
+
+PresentationServiceDelegateObservers::PresentationServiceDelegateObservers() {}
+
+PresentationServiceDelegateObservers::~PresentationServiceDelegateObservers() {
+  for (auto& observer_pair : observers_)
+    observer_pair.second->OnDelegateDestroyed();
+}
+
+void PresentationServiceDelegateObservers::AddObserver(
+    int render_process_id,
+    int render_frame_id,
+    content::PresentationServiceDelegate::Observer* observer) {
+  DCHECK(observer);
+
+  RenderFrameHostId rfh_id(render_process_id, render_frame_id);
+  DCHECK(!base::ContainsKey(observers_, rfh_id));
+  observers_[rfh_id] = observer;
+}
+
+void PresentationServiceDelegateObservers::RemoveObserver(int render_process_id,
+                                                          int render_frame_id) {
+  observers_.erase(RenderFrameHostId(render_process_id, render_frame_id));
+}
+
+}  // namespace media_router