Support (E)AC3 passthrough

media/filters/audio_renderer_algorithm.cc

Index: media/filters/audio_renderer_algorithm.cc
diff --git a/media/filters/audio_renderer_algorithm.cc b/media/filters/audio_renderer_algorithm.cc
index ebe334a0f1a0c76c1063ed1c79512cc36fd4c6bb..18f3bbdf9fdd89c78bf5855ac0367ecabd7eb7bb 100644
--- a/media/filters/audio_renderer_algorithm.cc
+++ b/media/filters/audio_renderer_algorithm.cc
@@ -67,6 +67,7 @@ static const int kStartingCapacityInMs = 200;
 AudioRendererAlgorithm::AudioRendererAlgorithm()
     : channels_(0),
       samples_per_second_(0),
+      is_raw_format_(false),
       muted_partial_frame_(0),
       capacity_(0),
       output_time_(0.0),
@@ -87,6 +88,7 @@ void AudioRendererAlgorithm::Initialize(const AudioParameters& params) {
 
   channels_ = params.channels();
   samples_per_second_ = params.sample_rate();
+  is_raw_format_ = params.IsRawFormat();
   initial_capacity_ = capacity_ =
       std::max(params.frames_per_buffer() * 2,
                ConvertMillisecondsToFrames(kStartingCapacityInMs));
@@ -149,6 +151,14 @@ int AudioRendererAlgorithm::FillBuffer(AudioBus* dest,
   DCHECK_GT(playback_rate, 0);
   DCHECK_EQ(channels_, dest->channels());
 
+  dest->set_is_raw_format(is_raw_format_);
+  if (is_raw_format_) {
+    dest->set_data_size(0);
+    dest->set_frames(0);
+
+    return audio_buffer_.ReadFrames(requested_frames, dest_offset, dest);
+  }
+
   // Optimize the muted case to issue a single clear instead of performing
   // the full crossfade and clearing each crossfaded frame.
   if (playback_rate < kMinPlaybackRate || playback_rate > kMaxPlaybackRate) {