Convert media constants to constexpr.

media/filters/ffmpeg_audio_decoder.cc

 // Copyright (c) 2012 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 "media/filters/ffmpeg_audio_decoder.h"
 
 #include <stdint.h>
 
 #include "base/callback_helpers.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 207 matching lines @@
     const scoped_refptr<DecoderBuffer>& buffer,
     const DecodeCB& decode_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_NE(state_, kUninitialized);
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK_NE(state_, kError);
   DCHECK(buffer.get());
 
   // Make sure we are notified if http://crbug.com/49709 returns.  Issue also
   // occurs with some damaged files.
-  if (!buffer->end_of_stream() && buffer->timestamp() == kNoTimestamp()) {
+  if (!buffer->end_of_stream() && buffer->timestamp() == kNoTimestamp) {
     DVLOG(1) << "Received a buffer without timestamps!";
     decode_cb.Run(DecodeStatus::DECODE_ERROR);
     return;
   }
 
   bool has_produced_frame;
   do {
     has_produced_frame = false;
     if (!FFmpegDecode(buffer, &has_produced_frame)) {
       state_ = kError;
@@ skipping 192 matching lines @@
   return true;
 }
 
 void FFmpegAudioDecoder::ResetTimestampState() {
   discard_helper_.reset(new AudioDiscardHelper(config_.samples_per_second(),
                                                config_.codec_delay()));
   discard_helper_->Reset(config_.codec_delay());
 }
 
 }  // namespace media