[Chromecast] Log sample rate changes and tweak audio logging output.

chromecast/media/cma/backend/alsa/audio_decoder_alsa.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/backend/alsa/audio_decoder_alsa.h"
 
 #include <time.h>
 
 #include <algorithm>
 #include <limits>
@@ skipping 212 matching lines @@
 }
 
 AudioDecoderAlsa::RenderingDelay AudioDecoderAlsa::GetRenderingDelay() {
   TRACE_FUNCTION_ENTRY0();
   return last_known_delay_;
 }
 
 void AudioDecoderAlsa::OnDecoderInitialized(bool success) {
   TRACE_FUNCTION_ENTRY0();
   DCHECK(task_runner_->BelongsToCurrentThread());
-  LOG(INFO) << "Decoder initialization returned with success = " << success;
+  LOG(INFO) << "Decoder initialization was "
+            << (success ? "successful" : "unsuccessful");
   if (!success)
     delegate_->OnDecoderError();
 }
 
 void AudioDecoderAlsa::OnBufferDecoded(
     uint64_t input_bytes,
     CastAudioDecoder::Status status,
     const scoped_refptr<DecoderBufferBase>& decoded) {
   TRACE_FUNCTION_ENTRY0();
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ skipping 38 matching lines @@
   if (delay.timestamp_microseconds != kInvalidDelayTimestamp)
     last_known_delay_ = delay;
   delegate_->OnPushBufferComplete(status);
   if (is_eos_)
     delegate_->OnEndOfStream();
 }
 
 void AudioDecoderAlsa::OnMixerError() {
   TRACE_FUNCTION_ENTRY0();
   DCHECK(task_runner_->BelongsToCurrentThread());
-  LOG(ERROR) << "Mixer error occured.";
+  // TODO(jyw): properly avoid outputting this message when it isn't needed
+  LOG(ERROR) << "Mixer error occurred. Did the sample rate just change?";
   error_ = true;
   delegate_->OnDecoderError();
 }
 
 }  // namespace media
 }  // namespace chromecast