Let Flash take one-shot focus in default MediaSession

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 "base/metrics/histogram_macros.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_content_type.h"
 #include "media/base/media_switches.h"
 
 namespace content {
 
+namespace {
+
+bool ShouldDuckFlash() {
+  return base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+             switches::kEnableDefaultMediaSession) ==
+         switches::kEnableDefaultMediaSessionDuckFlash;
+}
+
+}  // anonymous namespace
+
 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_.begin();
        iter != players_map_.end();) {
@@ skipping 11 matching lines @@
   UMA_HISTOGRAM_BOOLEAN("Media.Pepper.PlayedSound",
                         players_played_sound_map_[pp_instance]);
   players_played_sound_map_.erase(pp_instance);
 
   PepperStopsPlayback(pp_instance);
 }
 
 void PepperPlaybackObserver::PepperStartsPlayback(int32_t pp_instance) {
   players_played_sound_map_[pp_instance] = true;
 
-  if (base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
-          switches::kEnableDefaultMediaSession) !=
-      switches::kEnableDefaultMediaSessionWithFlash) {
-    return;
-  }
-
   if (players_map_.count(pp_instance))
     return;
 
   players_map_[pp_instance].reset(new PepperPlayerDelegate(
       contents_, pp_instance));
+
   MediaSession::Get(contents_)->AddPlayer(
-      players_map_[pp_instance].get(),
-      PepperPlayerDelegate::kPlayerId,
-      media::MediaContentType::Pepper);
+      players_map_[pp_instance].get(), PepperPlayerDelegate::kPlayerId,
+      ShouldDuckFlash() ? media::MediaContentType::Pepper
+                    : media::MediaContentType::Persistent);
 }
 
 void PepperPlaybackObserver::PepperStopsPlayback(int32_t pp_instance) {
   if (!players_map_.count(pp_instance))
     return;
 
   MediaSession::Get(contents_)->RemovePlayer(
       players_map_[pp_instance].get(), PepperPlayerDelegate::kPlayerId);
 
   players_map_.erase(pp_instance);
 }
 
 }  // namespace content