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

chrome/browser/media/router/presentation_service_delegate_base_impl.cc

+// Copyright 2015 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_base_impl.h"
+
+#include <unordered_map>

[mark a. foltz, 2016/11/15 23:41:46]

Is this needed?

[zhaobin, 2016/11/16 18:02:40]

Done.

+
+#include "content/public/browser/render_frame_host.h"
+
+using content::RenderFrameHost;

[mark a. foltz, 2016/11/15 23:41:46]

Ditto

[zhaobin, 2016/11/16 18:02:40]

Done.

+
+namespace media_router {
+
+PresentationServiceDelegateBaseImpl::PresentationServiceDelegateBaseImpl() {}
+
+PresentationServiceDelegateBaseImpl::~PresentationServiceDelegateBaseImpl() {
+  for (auto& observer_pair : observers_)
+    observer_pair.second->OnDelegateDestroyed();
+}
+
+void PresentationServiceDelegateBaseImpl::AddObserver(
+    int render_process_id,
+    int render_frame_id,
+    content::PresentationServiceDelegateBase::Observer* observer) {
+  DCHECK(observer);
+
+  RenderFrameHostId rfh_id(render_process_id, render_frame_id);
+  DCHECK(!base::ContainsKey(observers_, rfh_id));
+  observers_[rfh_id] = observer;

[mark a. foltz, 2016/11/15 23:41:46]

If the DCHECKS would have failed above in a release build, then the observer map
willb e left be in a bad state (possibly containing a missing or nullptr
observer).

Do you think it would be better to convert the DCHECKs to an if/else with
LOG(SEVERE) to leave the map in its previous state?

I am leaning towards keeping the DCHECKs since they will find the problem
quickly in tests and debug builds, while logs are easily ignored.  WDYT?

[zhaobin, 2016/11/16 18:02:39]

I dont have strong opinions but slightly prefer DCHECKs - it crashes earlier in
debug build and makes the code cleaner.

+}
+
+void PresentationServiceDelegateBaseImpl::RemoveObserver(int render_process_id,
+                                                         int render_frame_id) {
+  observers_.erase(RenderFrameHostId(render_process_id, render_frame_id));
+}
+
+}  // namespace media_router