media: Prefer decrypting pipeline when CDM is attached

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 7649469035bc82dfc12698f6e5dae28dfb8547d5..719e9adcc5105ae472ef332963c6ecde9833fa6e 100644
--- a/media/filters/decrypting_audio_decoder.cc
+++ b/media/filters/decrypting_audio_decoder.cc
@@ -58,6 +58,7 @@ void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(decode_cb_.is_null());
   DCHECK(reset_cb_.is_null());
+  DCHECK(cdm_context);
 
   weak_this_ = weak_factory_.GetWeakPtr();
   init_cb_ = BindToCurrentLoop(init_cb);
@@ -73,11 +74,6 @@ void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
   config_ = config;
 
   if (state_ == kUninitialized) {
-    // DecoderSelector only chooses |this| when the stream is encrypted.
-    // TODO(xhwang): We may also select this decoder for clear stream if a CDM
-    // is attached. Then we need to update this. See http://crbug.com/597443
-    DCHECK(config.is_encrypted());
-    DCHECK(cdm_context);
     if (!cdm_context->GetDecryptor()) {
       MEDIA_LOG(DEBUG, media_log_) << GetDisplayName() << ": no decryptor";
       base::ResetAndReturn(&init_cb_).Run(false);