Mojo interfaces needed for switching audio rendering stream creation and closing from IPC to Mojo

media/audio/audio_parameters.h

Index: media/audio/audio_parameters.h
diff --git a/media/audio/audio_parameters.h b/media/audio/audio_parameters.h
index d7d730b91497b1a6bd145961c5ce7b6e0ec6f2c1..3842c5a0f95d4f2544c22c4ae4d29185985e2591 100644
--- a/media/audio/audio_parameters.h
+++ b/media/audio/audio_parameters.h
@@ -151,6 +151,7 @@ class MEDIA_EXPORT AudioParameters {
            channels == ChannelLayoutToChannelCount(channel_layout_));
     channels_ = channels;
   }
+  void set_channels(int channels) { channels_ = channels; }
   int channels() const { return channels_; }
 
   void set_sample_rate(int sample_rate) { sample_rate_ = sample_rate; }