media: Make MediaKeys ref-counted.

media/base/android/media_source_player.cc

Index: media/base/android/media_source_player.cc
diff --git a/media/base/android/media_source_player.cc b/media/base/android/media_source_player.cc
index d4408b31396a02d90d20e912e1b75951d6950af6..453138965cf31cb3cbf99a8bad029fb36437d86e 100644
--- a/media/base/android/media_source_player.cc
+++ b/media/base/android/media_source_player.cc
@@ -39,7 +39,7 @@ MediaSourcePlayer::MediaSourcePlayer(
       interpolator_(&default_tick_clock_),
       doing_browser_seek_(false),
       pending_seek_(false),
-      drm_bridge_(NULL),
+      drm_bridge_(nullptr),
       cdm_registration_id_(0),
       is_waiting_for_key_(false),
       key_added_while_decode_pending_(false),
@@ -69,8 +69,8 @@ MediaSourcePlayer::MediaSourcePlayer(
 
 MediaSourcePlayer::~MediaSourcePlayer() {
   Release();
-  DCHECK_EQ(!drm_bridge_, !cdm_registration_id_);
-  if (drm_bridge_) {
+  DCHECK_EQ(!cdm_, !cdm_registration_id_);
+  if (cdm_) {
     drm_bridge_->UnregisterPlayer(cdm_registration_id_);

[Tima Vaisburd, 2015/10/28 22:49:40]

Same consideration as with MediaCodecPlayer: I would use a cast and keep just
one member var that points to one object.

[xhwang, 2015/10/29 00:17:28]

Done.

     cdm_registration_id_ = 0;
   }
@@ -273,7 +273,9 @@ void MediaSourcePlayer::OnMediaCryptoReady(
   RetryDecoderCreation(true, true);
 }
 
-void MediaSourcePlayer::SetCdm(BrowserCdm* cdm) {
+void MediaSourcePlayer::SetCdm(const scoped_refptr<MediaKeys>& cdm) {
+  DCHECK(cdm);
+
   // Currently we don't support DRM change during the middle of playback, even
   // if the player is paused.
   // TODO(qinmin): support DRM change after playback has started.
@@ -283,13 +285,15 @@ void MediaSourcePlayer::SetCdm(BrowserCdm* cdm) {
             << "This is not well supported!";
   }
 
-  if (drm_bridge_) {
+  if (cdm_) {
     NOTREACHED() << "Currently we do not support resetting CDM.";
     return;
   }
 
+  cdm_ = cdm;
+
   // Only MediaDrmBridge will be set on MediaSourcePlayer.
-  drm_bridge_ = static_cast<MediaDrmBridge*>(cdm);
+  drm_bridge_ = static_cast<MediaDrmBridge*>(cdm_.get());
 
   cdm_registration_id_ = drm_bridge_->RegisterPlayer(
       base::Bind(&MediaSourcePlayer::OnKeyAdded, weak_this_),
@@ -299,6 +303,7 @@ void MediaSourcePlayer::SetCdm(BrowserCdm* cdm) {
   video_decoder_job_->SetDrmBridge(drm_bridge_);
 
   if (drm_bridge_->GetMediaCrypto().is_null()) {
+    // Use BindToCurrentLoop to avoid reentrancy.
     MediaDrmBridge::MediaCryptoReadyCB cb = BindToCurrentLoop(
         base::Bind(&MediaSourcePlayer::OnMediaCryptoReady, weak_this_));
     drm_bridge_->SetMediaCryptoReadyCB(cb);
@@ -837,16 +842,17 @@ void MediaSourcePlayer::ResumePlaybackAfterKeyAdded() {
 
 void MediaSourcePlayer::OnCdmUnset() {
   DVLOG(1) << __FUNCTION__;
-  DCHECK(drm_bridge_);
+  DCHECK(cdm_);
   // TODO(xhwang): Currently this is only called during teardown. Support full
   // detachment of CDM during playback. This will be needed when we start to
   // support setMediaKeys(0) (see http://crbug.com/330324), or when we release
   // MediaDrm when the video is paused, or when the device goes to sleep (see
   // http://crbug.com/272421).
-  audio_decoder_job_->SetDrmBridge(NULL);
-  video_decoder_job_->SetDrmBridge(NULL);
+  audio_decoder_job_->SetDrmBridge(nullptr);
+  video_decoder_job_->SetDrmBridge(nullptr);
   cdm_registration_id_ = 0;
-  drm_bridge_ = NULL;
+  drm_bridge_ = nullptr;
+  cdm_ = nullptr;
 }
 
 }  // namespace media