media: Allow config change between clear and encrypted streams

media/filters/decrypting_video_decoder.cc

Index: media/filters/decrypting_video_decoder.cc
diff --git a/media/filters/decrypting_video_decoder.cc b/media/filters/decrypting_video_decoder.cc
index 1b541d96231644c33047c5b4e834408bb669d7d6..3a869440d4f1e52e6f8cca1b79db9699b363bfa6 100644
--- a/media/filters/decrypting_video_decoder.cc
+++ b/media/filters/decrypting_video_decoder.cc
@@ -52,7 +52,6 @@ void DecryptingVideoDecoder::Initialize(const VideoDecoderConfig& config,
   DCHECK(decode_cb_.is_null());
   DCHECK(reset_cb_.is_null());
   DCHECK(config.IsValidConfig());
-  DCHECK(config.is_encrypted());
 
   init_cb_ = BindToCurrentLoop(init_cb);
   output_cb_ = BindToCurrentLoop(output_cb);
@@ -60,6 +59,10 @@ void DecryptingVideoDecoder::Initialize(const VideoDecoderConfig& 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";
@@ -69,7 +72,8 @@ void DecryptingVideoDecoder::Initialize(const VideoDecoderConfig& config,
 
     decryptor_ = cdm_context->GetDecryptor();
   } else {
-    // Reinitialization.
+    // Reinitialization (i.e. upon a config change). The new config can be
+    // encrypted or clear.
     decryptor_->DeinitializeDecoder(Decryptor::kVideo);
   }