media: Allow config change between clear and encrypted streams

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 6ae354c47b3cd9b999a61c329a3169451e7943e0..ebedc839f1c0014c9603b53116fa7fd3ffbf031a 100644
--- a/media/filters/decrypting_audio_decoder.cc
+++ b/media/filters/decrypting_audio_decoder.cc
@@ -63,23 +63,18 @@ void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
   init_cb_ = BindToCurrentLoop(init_cb);
   output_cb_ = BindToCurrentLoop(output_cb);
 
-  // TODO(xhwang): We should be able to DCHECK config.IsValidConfig() and
-  // config.is_encrypted().
+  // TODO(xhwang): We should be able to DCHECK config.IsValidConfig().
   if (!config.IsValidConfig()) {
     DLOG(ERROR) << "Invalid audio stream config.";
     base::ResetAndReturn(&init_cb_).Run(false);
     return;
   }
 
-  // DecryptingAudioDecoder only accepts potentially encrypted stream.
-  if (!config.is_encrypted()) {
-    base::ResetAndReturn(&init_cb_).Run(false);
-    return;
-  }
-
   config_ = config;
 
   if (state_ == kUninitialized) {
+    // DecoderSelector only chooses |this| when the stream is encrypted.

[ddorwin, 2017/02/12 04:28:52]

This will change in the next CL, right? Maybe add a TODO so that's clear for
anyone doing archaeology.

[xhwang, 2017/02/14 23:59:32]

Done.

+    DCHECK(config.is_encrypted());
     DCHECK(cdm_context);
     if (!cdm_context->GetDecryptor()) {
       MEDIA_LOG(DEBUG, media_log_) << GetDisplayName() << ": no decryptor";
@@ -89,7 +84,8 @@ void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
 
     decryptor_ = cdm_context->GetDecryptor();
   } else {
-    // Reinitialization (i.e. upon a config change)
+    // Reinitialization (i.e. upon a config change). The new config can be
+    // encrypted or clear.
     decryptor_->DeinitializeDecoder(Decryptor::kAudio);
   }