Convert media constants to constexpr.

chromecast/media/cma/decoder/cast_audio_decoder_linux.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromecast/media/cma/decoder/cast_audio_decoder.h"
 
 #include <stdint.h>
 #include <limits>
 #include <queue>
 #include <utility>
@@ skipping 119 matching lines @@
       // Post the task to ensure that |decode_callback| is not called from
       // within a call to Decode().
       task_runner_->PostTask(FROM_HERE,
                              base::Bind(decode_callback, kDecodeOk, data));
       return;
     }
 
     // FFmpegAudioDecoder requires a timestamp to be set.
     base::TimeDelta timestamp =
         base::TimeDelta::FromMicroseconds(data->timestamp());
-    if (timestamp == ::media::kNoTimestamp())
+    if (timestamp == ::media::kNoTimestamp)
       data->set_timestamp(base::TimeDelta());
 
     decode_pending_ = true;
     decoder_->Decode(
         data->ToMediaBuffer(),
         base::Bind(&CastAudioDecoderImpl::OnDecodeStatus,
                    weak_factory_.GetWeakPtr(), timestamp, decode_callback));
   }
 
   void OnInitialized(bool success) {
@@ skipping 146 matching lines @@
       return 2;
     case CastAudioDecoder::OutputFormat::kOutputPlanarFloat:
       return 4;
   }
   NOTREACHED();
   return 1;
 }
 
 }  // namespace media
 }  // namespace chromecast