Allow setContentDecryptionModule() to get called when setting is done.

media/filters/decrypting_audio_decoder.cc

Index: media/filters/decrypting_audio_decoder.cc
diff --git a/media/filters/decrypting_audio_decoder.cc b/media/filters/decrypting_audio_decoder.cc
index 79d82093302c313de8265bdf27408a76d2f0429e..aae0afa0682e54bfd6b1d1153e86924cd18a3780 100644
--- a/media/filters/decrypting_audio_decoder.cc
+++ b/media/filters/decrypting_audio_decoder.cc
@@ -166,7 +166,8 @@ DecryptingAudioDecoder::~DecryptingAudioDecoder() {
     base::ResetAndReturn(&reset_cb_).Run();
 }
 
-void DecryptingAudioDecoder::SetDecryptor(Decryptor* decryptor) {
+void DecryptingAudioDecoder::SetDecryptor(Decryptor* decryptor,
+                                          const base::Closure& done_cb) {
   DVLOG(2) << "SetDecryptor()";
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kDecryptorRequested) << state_;
@@ -178,12 +179,14 @@ void DecryptingAudioDecoder::SetDecryptor(Decryptor* decryptor) {
   if (!decryptor) {
     base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
     state_ = kError;
+    done_cb.Run();

[ddorwin, 2014/07/30 22:35:46]

Shouldn't this reject the promise?
How can we get here?

[jrummell, 2014/08/01 22:09:42]

This is called with NULL if there is a previous decryptor reference pending
(https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/m...),
and may get called if we enable support for setting mediaKeys = null (step 3.2.3
of setMediakeys(mediaKeys) in the EME spec). Since it currently doesn't stop
this decoder from using the decryptor, it makes sense to fail the promise. Added
a bool parameter to indicate success/failure.

     return;
   }
 
   decryptor_ = decryptor;
 
   InitializeDecoder();
+  done_cb.Run();
 }
 
 void DecryptingAudioDecoder::InitializeDecoder() {