Refactor audio and video decoder status into common file.

chromecast/media/cma/decoder/cast_audio_decoder_linux.cc

Index: chromecast/media/cma/decoder/cast_audio_decoder_linux.cc
diff --git a/chromecast/media/cma/decoder/cast_audio_decoder_linux.cc b/chromecast/media/cma/decoder/cast_audio_decoder_linux.cc
index d0b8bc4079ee90c2a09a9250b0568060b957e240..316363c21a998e42c1441d8c087c413eb177ced5 100644
--- a/chromecast/media/cma/decoder/cast_audio_decoder_linux.cc
+++ b/chromecast/media/cma/decoder/cast_audio_decoder_linux.cc
@@ -184,13 +184,13 @@ class CastAudioDecoderImpl : public CastAudioDecoder {
 
   void OnDecodeStatus(base::TimeDelta buffer_timestamp,
                       const DecodeCallback& decode_callback,
-                      ::media::AudioDecoder::Status status) {
+                      ::media::DecodeStatus status) {
     Status result_status = kDecodeOk;
     scoped_refptr<media::DecoderBufferBase> decoded;
-    if (status == ::media::AudioDecoder::kOk && !decoded_chunks_.empty()) {
+    if (status == ::media::DecodeStatus::OK && !decoded_chunks_.empty()) {
       decoded = ConvertDecoded();
     } else {
-      if (status != ::media::AudioDecoder::kOk)
+      if (status != ::media::DecodeStatus::OK)
         result_status = kDecodeError;
       decoded = new media::DecoderBufferAdapter(config_.id,
                                                 new ::media::DecoderBuffer(0));