Move audio focus control from media/ to content/ and make it per WebContents.

content/browser/media/android/browser_media_player_manager.cc

Index: content/browser/media/android/browser_media_player_manager.cc
diff --git a/content/browser/media/android/browser_media_player_manager.cc b/content/browser/media/android/browser_media_player_manager.cc
index 68268f7406d215d98953787c36061d5b870c0f8f..9ce89a65daacc2ade3be4e9fee9a0983b759683a 100644
--- a/content/browser/media/android/browser_media_player_manager.cc
+++ b/content/browser/media/android/browser_media_player_manager.cc
@@ -10,6 +10,7 @@
 #include "content/browser/android/media_players_observer.h"
 #include "content/browser/media/android/browser_demuxer_android.h"
 #include "content/browser/media/android/media_resource_getter_impl.h"
+#include "content/browser/media/android/media_session.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_view_android.h"
 #include "content/common/media/media_player_messages_android.h"
@@ -44,6 +45,9 @@ namespace content {
 const int kMediaPlayerThreshold = 1;
 const int kInvalidMediaPlayerId = -1;
 
+// Minimal duration of a media player in order to be considered as Content type.
+const int kMinimumDurationForContentInSeconds = 5;
+
 static BrowserMediaPlayerManager::Factory g_factory = NULL;
 static media::MediaUrlInterceptor* media_url_interceptor_ = NULL;
 
@@ -160,6 +164,7 @@ BrowserMediaPlayerManager::~BrowserMediaPlayerManager() {
   for (MediaPlayerAndroid* player : players_)
     player->DeleteOnCorrectThread();
 
+  MediaSession::Get(web_contents())->RemovePlayers(this);
   players_.weak_clear();
 }
 
@@ -228,6 +233,8 @@ void BrowserMediaPlayerManager::OnMediaMetadataChanged(
 
 void BrowserMediaPlayerManager::OnPlaybackComplete(int player_id) {
   Send(new MediaPlayerMsg_MediaPlaybackCompleted(RoutingID(), player_id));
+  MediaSession::Get(web_contents())->RemovePlayer(this, player_id);
+
   if (fullscreen_player_id_ == player_id)
     video_view_->OnPlaybackComplete();
 }
@@ -341,6 +348,21 @@ void BrowserMediaPlayerManager::RequestFullScreen(int player_id) {
   Send(new MediaPlayerMsg_RequestFullscreen(RoutingID(), player_id));
 }
 
+bool BrowserMediaPlayerManager::RequestPlay(int player_id) {
+  MediaPlayerAndroid* player = GetPlayer(player_id);
+  DCHECK(player);
+
+  MediaSession::Type media_session_type =
+      player->GetDuration().InSeconds() > kMinimumDurationForContentInSeconds
+          ? MediaSession::Type::Content : MediaSession::Type::Transient;
+
+  bool succeeded = MediaSession::Get(web_contents())->AddPlayer(
+      this, player_id, media_session_type);
+  if (!succeeded)
+    OnSuspend(player_id);

[qinmin, 2015/05/20 21:35:24]

MediaPlayerAndroid::RequestPlay() could possibly call
MediaPlayerAndroid::Pause(), the reentrance makes the code very fragile to
errors.
And the logic is also wierd, if RequestPlay() returns false, shouldn't the
player handle the failed start() call by itself? Rather than letting the manager
calling pause for it.

[mlamouri (slow - plz ping), 2015/05/22 15:58:52]

It's something I actually fixed while writing unit tests for the player.

+  return succeeded;
+}
+
 #if defined(VIDEO_HOLE)
 void BrowserMediaPlayerManager::AttachExternalVideoSurface(int player_id,
                                                            jobject surface) {
@@ -365,6 +387,22 @@ void BrowserMediaPlayerManager::OnFrameInfoUpdated() {
     external_video_surface_container_->OnFrameInfoUpdated();
 }
 
+void BrowserMediaPlayerManager::OnSuspend(int player_id) {
+  MediaPlayerAndroid* player = GetPlayer(player_id);
+  DCHECK(player);
+
+  player->Pause(true);
+  Send(new MediaPlayerMsg_DidMediaPlayerPause(RoutingID(), player_id));
+}
+
+void BrowserMediaPlayerManager::OnResume(int player_id) {
+  MediaPlayerAndroid* player = GetPlayer(player_id);
+  DCHECK(player);
+
+  player->Start();
+  Send(new MediaPlayerMsg_DidMediaPlayerPlay(RoutingID(), player_id));
+}
+
 void BrowserMediaPlayerManager::OnNotifyExternalSurface(
     int player_id, bool is_request, const gfx::RectF& rect) {
   if (!web_contents_)
@@ -503,6 +541,8 @@ void BrowserMediaPlayerManager::OnPause(
   MediaPlayerAndroid* player = GetPlayer(player_id);
   if (player)
     player->Pause(is_media_related_action);
+
+  MediaSession::Get(web_contents())->RemovePlayer(this, player_id);
 }
 
 void BrowserMediaPlayerManager::OnSetVolume(int player_id, double volume) {