Let Flash join and be controlled by media session

content/browser/media/session/pepper_playback_observer.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/browser/media/session/pepper_playback_observer.h"
+
+#include "base/feature_list.h"
+#include "content/browser/media/session/media_session.h"
+#include "content/browser/media/session/pepper_player_delegate.h"
+#include "content/common/frame_messages.h"
+#include "ipc/ipc_message_macros.h"
+#include "media/base/media_switches.h"
+
+namespace content {
+
+namespace {
+
+const int kPlayerId = 0;
+
+}
+
+PepperPlaybackObserver::PepperPlaybackObserver(WebContentsImpl *contents)
+    : contents_(contents) {}
+
+PepperPlaybackObserver::~PepperPlaybackObserver() {
+  // At this point WebContents is being destructed, so it's safe to
+  // call this. MediaSession may decide to send further IPC messages
+  // through PepperPlayerDelegates, which might be declined if the
+  // RenderViewHost has been destroyed.
+  for (PlayersMap::iterator iter(&players_map_);
+       !iter.IsAtEnd(); iter.Advance()) {
+    PepperStopsPlayback(iter.GetCurrentKey());
+  }
+}
+
+void PepperPlaybackObserver::PepperInstanceCreated(int32_t pp_instance) {
+}
+
+void PepperPlaybackObserver::PepperInstanceDeleted(int32_t pp_instance) {
+  PepperStopsPlayback(pp_instance);
+}
+
+void PepperPlaybackObserver::PepperStartsPlayback(int32_t pp_instance) {
+  if (!base::FeatureList::IsEnabled(media::kFlashJoinsMediaSession))
+    return;
+
+  if (players_map_.Lookup(pp_instance))
+    return;
+
+  players_map_.AddWithID(new PepperPlayerDelegate(
+      contents_, pp_instance), pp_instance);
+  MediaSession::Get(contents_)->AddPlayer(
+      players_map_.Lookup(pp_instance), kPlayerId, MediaSession::Type::Content);
+}
+
+void PepperPlaybackObserver::PepperStopsPlayback(int32_t pp_instance) {
+  if (!players_map_.Lookup(pp_instance))
+    return;
+
+  MediaSession::Get(contents_)->RemovePlayer(
+      players_map_.Lookup(pp_instance), kPlayerId);
+
+  players_map_.Remove(pp_instance);
+}
+
+}  // namespace content