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

content/public/browser/presentation_service_delegate.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 "content/public/browser/presentation_service_delegate.h"
+
+namespace content {
+
+PresentationServiceDelegate::PresentationServiceDelegate() {}
+
+PresentationServiceDelegate::~PresentationServiceDelegate() {
+  for (auto& observer_pair : observers_)
+    observer_pair.second->OnDelegateDestroyed();
+}
+
+void PresentationServiceDelegate::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 PresentationServiceDelegate::RemoveObserver(int render_process_id,
+                                                 int render_frame_id) {
+  observers_.erase(RenderFrameHostID(render_process_id, render_frame_id));
+}
+
+}  // namespace content