Convert //chromecast from scoped_ptr to std::unique_ptr

chromecast/media/cma/decoder/cast_audio_decoder_android.cc

Index: chromecast/media/cma/decoder/cast_audio_decoder_android.cc
diff --git a/chromecast/media/cma/decoder/cast_audio_decoder_android.cc b/chromecast/media/cma/decoder/cast_audio_decoder_android.cc
index 669c688b8d503d6256c4e7a40ce771c65c64f0b9..d0112809432920b7fea14ca3a886e2b4a6d8e5d4 100644
--- a/chromecast/media/cma/decoder/cast_audio_decoder_android.cc
+++ b/chromecast/media/cma/decoder/cast_audio_decoder_android.cc
@@ -10,12 +10,12 @@ namespace chromecast {
 namespace media {
 
 // static
-scoped_ptr<CastAudioDecoder> CastAudioDecoder::Create(
+std::unique_ptr<CastAudioDecoder> CastAudioDecoder::Create(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     const media::AudioConfig& config,
     OutputFormat output_format,
     const InitializedCallback& initialized_callback) {
-  return scoped_ptr<CastAudioDecoder>();
+  return std::unique_ptr<CastAudioDecoder>();
 }
 
 // static