Decryptors can report kNoKey to WebMediaPlayer

media/filters/decrypting_video_decoder.h

Index: media/filters/decrypting_video_decoder.h
diff --git a/media/filters/decrypting_video_decoder.h b/media/filters/decrypting_video_decoder.h
index 8e40502cb13f83541708a637e06846bdf4f4c9e9..2d66e440965ad19f9f5ba44c011c8f84fe5e0952 100644
--- a/media/filters/decrypting_video_decoder.h
+++ b/media/filters/decrypting_video_decoder.h
@@ -36,7 +36,8 @@ class MEDIA_EXPORT DecryptingVideoDecoder : public VideoDecoder {
   void Initialize(const VideoDecoderConfig& config,
                   bool low_delay,
                   const PipelineStatusCB& status_cb,
-                  const OutputCB& output_cb) override;
+                  const OutputCB& output_cb,
+                  const base::Closure& waiting_for_encryption_key_cb) override;
   void Decode(const scoped_refptr<DecoderBuffer>& buffer,
               const DecodeCB& decode_cb) override;
   void Reset(const base::Closure& closure) override;
@@ -88,6 +89,7 @@ class MEDIA_EXPORT DecryptingVideoDecoder : public VideoDecoder {
   OutputCB output_cb_;
   DecodeCB decode_cb_;
   base::Closure reset_cb_;
+  base::Closure waiting_for_encryption_key_cb_;
 
   VideoDecoderConfig config_;