Support (E)AC3 passthrough

content/browser/renderer_host/media/audio_sync_reader.cc

Index: content/browser/renderer_host/media/audio_sync_reader.cc
diff --git a/content/browser/renderer_host/media/audio_sync_reader.cc b/content/browser/renderer_host/media/audio_sync_reader.cc
index 6299aaf7e665b038956893ef87a562dac5a623af..2b3fd17c7f81b07f0bad56a3448dc8da2a2fd7cb 100644
--- a/content/browser/renderer_host/media/audio_sync_reader.cc
+++ b/content/browser/renderer_host/media/audio_sync_reader.cc
@@ -71,6 +71,7 @@ AudioSyncReader::AudioSyncReader(
       reinterpret_cast<AudioOutputBuffer*>(shared_memory_->memory());
   output_bus_ = AudioBus::WrapMemory(params, buffer->audio);
   output_bus_->Zero();
+  output_bus_->set_is_raw_format(params.IsRawFormat());
 }
 
 AudioSyncReader::~AudioSyncReader() {
@@ -176,8 +177,15 @@ void AudioSyncReader::Read(AudioBus* dest) {
 
   if (mute_audio_)
     dest->Zero();
-  else
+  else {
+    if (output_bus_->is_raw_format()) {
+      AudioOutputBuffer* buffer =
+          reinterpret_cast<AudioOutputBuffer*>(shared_memory_->memory());
+      output_bus_->set_frames(buffer->params.frames);
+      output_bus_->set_data_size(buffer->params.data_size);
+    }
     output_bus_->CopyTo(dest);
+  }
 }
 
 void AudioSyncReader::Close() {