media: Refactor MediaCrypto creation and notification.

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 8aec0ab31f907c76f5cfcae34d2b4a707390bde8..38afb9a30850b3baf6ed80d26b0655f4c7adacf9 100644
--- a/media/base/android/media_source_player.cc
+++ b/media/base/android/media_source_player.cc
@@ -266,11 +266,16 @@ void MediaSourcePlayer::OnDemuxerDurationChanged(base::TimeDelta duration) {
 }
 
 void MediaSourcePlayer::OnMediaCryptoReady(
-    MediaDrmBridge::JavaObjectPtr /* media_crypto */,
+    MediaDrmBridge::JavaObjectPtr media_crypto,
     bool /* needs_protected_surface */) {
-  // Callback parameters are ignored in this player. They are intended for
-  // MediaCodecPlayer which uses a different threading scheme.
-  DCHECK(!static_cast<MediaDrmBridge*>(cdm_.get())->GetMediaCrypto().is_null());
+  DCHECK(media_crypto);
+  DCHECK(static_cast<MediaDrmBridge*>(cdm_.get())->GetMediaCrypto());
+
+  if (media_crypto->is_null()) {
+    // TODO(xhwang): Fail playback nicely here.

[Tima Vaisburd, 2015/12/11 19:31:24]

The normal reaction to internal error seems to be
    Release();
    manager()->OnError(player_id(), MEDIA_ERROR_DECODE);

Should we put it here and this would conclude TODO? 

[xhwang, 2015/12/11 21:45:16]

As discussed offline. Refined the TODO and we'll consider it in a separate CL.

+    LOG(ERROR) << "MediaCrypto creation failed!";
+    return;
+  }
 
   // Retry decoder creation if the decoders are waiting for MediaCrypto.
   RetryDecoderCreation(true, true);
@@ -306,16 +311,9 @@ void MediaSourcePlayer::SetCdm(const scoped_refptr<MediaKeys>& cdm) {
   audio_decoder_job_->SetDrmBridge(drm_bridge);
   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);
-    return;
-  }
-
-  // If the player is previously waiting for CDM, retry decoder creation.
-  RetryDecoderCreation(true, true);
+  // Use BindToCurrentLoop to avoid reentrancy.
+  drm_bridge->SetMediaCryptoReadyCB(BindToCurrentLoop(
+      base::Bind(&MediaSourcePlayer::OnMediaCryptoReady, weak_this_)));
 }
 
 void MediaSourcePlayer::OnDemuxerSeekDone(