Support (E)AC3 passthrough

media/base/audio_parameters.h

Index: media/base/audio_parameters.h
diff --git a/media/base/audio_parameters.h b/media/base/audio_parameters.h
index 2cb28c64bdfd5688f244324d1d80df0ba8fb9005..ca637792826fdede24f3fcd8b9ae385ea5f57677 100644
--- a/media/base/audio_parameters.h
+++ b/media/base/audio_parameters.h
@@ -41,6 +41,8 @@ struct MEDIA_EXPORT ALIGNAS(PARAMETERS_ALIGNMENT) AudioInputBufferParameters {
 };
 struct MEDIA_EXPORT ALIGNAS(PARAMETERS_ALIGNMENT) AudioOutputBufferParameters {
   uint32_t frames_skipped;
+  uint32_t frames;
+  uint32_t data_size;
 };
 #undef PARAMETERS_ALIGNMENT
 #if defined(OS_WIN)
@@ -72,6 +74,8 @@ class MEDIA_EXPORT AudioParameters {
   enum Format {
     AUDIO_PCM_LINEAR = 0,            // PCM is 'raw' amplitude samples.
     AUDIO_PCM_LOW_LATENCY,           // Linear PCM, low latency requested.
+    AUDIO_RAW_AC3,                   // Raw compressed AC3 bitstream.
+    AUDIO_RAW_EAC3,                  // Raw compressed E-AC3 bitstream.
     AUDIO_FAKE,                      // Creates a fake AudioOutputStream object.
     AUDIO_FORMAT_LAST = AUDIO_FAKE,  // Only used for validation of format.
   };
@@ -139,6 +143,9 @@ class MEDIA_EXPORT AudioParameters {
   // Comparison with other AudioParams.
   bool Equals(const AudioParameters& other) const;
 
+  // Return true if |format_| is raw compressed audio.
+  bool IsRawFormat() const;
+
   void set_format(Format format) { format_ = format; }
   Format format() const { return format_; }