Improve input handling for WaveAudioHandler.

media/audio/sounds/audio_stream_handler.cc

Index: media/audio/sounds/audio_stream_handler.cc
diff --git a/media/audio/sounds/audio_stream_handler.cc b/media/audio/sounds/audio_stream_handler.cc
index 5f175ea75ad97b1f073d67e76c1c7c20bb02e30e..c3a26aee0e9ceacad2156a0162214a8e0ae11cfc 100644
--- a/media/audio/sounds/audio_stream_handler.cc
+++ b/media/audio/sounds/audio_stream_handler.cc
@@ -36,12 +36,14 @@ AudioOutputStream::AudioSourceCallback* g_audio_source_for_testing = NULL;
 class AudioStreamHandler::AudioStreamContainer
     : public AudioOutputStream::AudioSourceCallback {
  public:
-  explicit AudioStreamContainer(const WavAudioHandler& wav_audio)
+  explicit AudioStreamContainer(scoped_ptr<WavAudioHandler> wav_audio)
       : started_(false),
         stream_(NULL),
         cursor_(0),
         delayed_stop_posted_(false),
-        wav_audio_(wav_audio) {}
+        wav_audio_(wav_audio.Pass()) {
+    DCHECK(wav_audio_);
+  }
 
   ~AudioStreamContainer() override {
     DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
@@ -53,8 +55,9 @@ class AudioStreamHandler::AudioStreamContainer
     if (!stream_) {
       const AudioParameters params(
           AudioParameters::AUDIO_PCM_LOW_LATENCY,
-          GuessChannelLayout(wav_audio_.num_channels()),
-          wav_audio_.sample_rate(), wav_audio_.bits_per_sample(),
+          GuessChannelLayout(wav_audio_->num_channels()),
+          wav_audio_->sample_rate(),
+          wav_audio_->bits_per_sample(),
           kDefaultFrameCount);
       stream_ = AudioManager::Get()->MakeAudioOutputStreamProxy(params,
                                                                 std::string());
@@ -73,7 +76,7 @@ class AudioStreamHandler::AudioStreamContainer
                                      base::Unretained(this)));
 
       if (started_) {
-        if (wav_audio_.AtEnd(cursor_))
+        if (wav_audio_->AtEnd(cursor_))
           cursor_ = 0;
         return;
       }
@@ -107,8 +110,8 @@ class AudioStreamHandler::AudioStreamContainer
     base::AutoLock al(state_lock_);
     size_t bytes_written = 0;
 
-    if (wav_audio_.AtEnd(cursor_) ||
-        !wav_audio_.CopyTo(dest, cursor_, &bytes_written)) {
+    if (wav_audio_->AtEnd(cursor_) ||
+        !wav_audio_->CopyTo(dest, cursor_, &bytes_written)) {
       if (delayed_stop_posted_)
         return 0;
       delayed_stop_posted_ = true;
@@ -150,29 +153,43 @@ class AudioStreamHandler::AudioStreamContainer
   base::Lock state_lock_;
   size_t cursor_;
   bool delayed_stop_posted_;
-  const WavAudioHandler wav_audio_;
+  scoped_ptr<WavAudioHandler> wav_audio_;
   base::CancelableClosure stop_closure_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioStreamContainer);
 };
 
 AudioStreamHandler::AudioStreamHandler(const base::StringPiece& wav_data)
-    : wav_audio_(wav_data),
-      initialized_(false) {
+    : initialized_(false) {
   AudioManager* manager = AudioManager::Get();
   if (!manager) {
     LOG(ERROR) << "Can't get access to audio manager.";
     return;
   }
-  const AudioParameters params(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY,
-      GuessChannelLayout(wav_audio_.num_channels()), wav_audio_.sample_rate(),
-      wav_audio_.bits_per_sample(), kDefaultFrameCount);
+
+  wav_audio_ = WavAudioHandler::Create(wav_data);
+  if (!wav_audio_) {
+    LOG(ERROR) << "wav_audio handler is not valid";
+    return;
+  }
+
+  const AudioParameters params(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                               GuessChannelLayout(wav_audio_->num_channels()),
+                               wav_audio_->sample_rate(),
+                               wav_audio_->bits_per_sample(),
+                               kDefaultFrameCount);
   if (!params.IsValid()) {
     LOG(ERROR) << "Audio params are invalid.";
     return;
   }
-  stream_.reset(new AudioStreamContainer(wav_audio_));
+
+  // Create an identical WavAudioHandler and pass it to AudioStreamContainer.
+  // This copy will be used on the AudioManager thread, and |wav_audio_| can
+  // safely be accessed on this thread via wav_audio_handler().
+  // TODO(slan): Find a way to use just one copy. This approach is silly.
+  auto wav_audio_copy = WavAudioHandler::Create(wav_data);
+  DCHECK(wav_audio_copy);
+  stream_.reset(new AudioStreamContainer(wav_audio_copy.Pass()));
   initialized_ = true;
 }