Add enumerations for compressed (E)AC3 sample format

media/base/audio_parameters.cc

Index: media/base/audio_parameters.cc
diff --git a/media/base/audio_parameters.cc b/media/base/audio_parameters.cc
index e3f9bb514257707935dbbe3bdbfd7f7ed3c330d5..2ae8c32422d2624c708c97fc17ef7fe793bd7d6a 100644
--- a/media/base/audio_parameters.cc
+++ b/media/base/audio_parameters.cc
@@ -97,6 +97,10 @@ bool AudioParameters::Equals(const AudioParameters& other) const {
          effects_ == other.effects() && mic_positions_ == other.mic_positions_;
 }
 
+bool AudioParameters::IsBitstreamFormat() const {
+  return format_ == AUDIO_BITSTREAM_AC3 || format_ == AUDIO_BITSTREAM_EAC3;
+}
+
 // static
 AudioParameters AudioParameters::UnavailableDeviceParams() {
   return media::AudioParameters(