Cast: Removed unnecessary ref counters.

media/cast/audio_receiver/audio_decoder.cc

Index: media/cast/audio_receiver/audio_decoder.cc
diff --git a/media/cast/audio_receiver/audio_decoder.cc b/media/cast/audio_receiver/audio_decoder.cc
index b140788fe04887c406a6b05095420f516dac56c1..1417221a38edcebbe2dac05969c0fe4425c7dae1 100644
--- a/media/cast/audio_receiver/audio_decoder.cc
+++ b/media/cast/audio_receiver/audio_decoder.cc
@@ -52,7 +52,7 @@ bool AudioDecoder::GetRawAudioFrame(int number_of_10ms_blocks,
                                     int desired_frequency,
                                     PcmAudioFrame* audio_frame,
                                     uint32* rtp_timestamp) {
-  if (!have_received_packets_) return false;
+  if (!base::subtle::NoBarrier_Load(&have_received_packets_)) return false;

[Alpha Left Google, 2013/11/15 19:40:39]

We very rarely use atomicops. What is the reason that we need them here? I
though this object is non-threadsafe so what are the threads that use this
object?

[pwestin, 2013/11/15 19:48:06]

I was looking for other options but did not find any simpler approach. 

GetRawAudioFrame is called from the cast audio decoder thread and
IncomingParsedRtpPacket is called from the Main cast thread

 
   audio_frame->samples.clear();
 
@@ -92,7 +92,7 @@ void AudioDecoder::IncomingParsedRtpPacket(const uint8* payload_data,
   DCHECK_LE(payload_size, kIpPacketSize);
   audio_decoder_->IncomingPacket(payload_data, static_cast<int32>(payload_size),
                                  rtp_header.webrtc);
-  have_received_packets_ = true;
+  base::subtle::NoBarrier_Store(&have_received_packets_, true);
 }
 
 }  // namespace cast