Tell CoreAudio how to interpret Chrome's channel layout.

media/audio/mac/audio_auhal_mac.h

Index: media/audio/mac/audio_auhal_mac.h
diff --git a/media/audio/mac/audio_auhal_mac.h b/media/audio/mac/audio_auhal_mac.h
index 146c492cdf7c75afef1fc69f3795439b0c54313d..90e8505c2c522f8a16b1003c84641495018bb510 100644
--- a/media/audio/mac/audio_auhal_mac.h
+++ b/media/audio/mac/audio_auhal_mac.h
@@ -23,6 +23,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <vector>
 
 #include "base/cancelable_callback.h"
 #include "base/compiler_specific.h"
@@ -141,6 +142,10 @@ class AUHALStream : public AudioOutputStream {
   // Called from the dtor and when the stream is reset.
   void ReportAndResetStats();
 
+  // Converts |params_.channel_layout()| into CoreAudio format and sets up the
+  // AUHAL with our layout information so it knows how to remap the channels.
+  void SetAudioChannelLayout();
+
   // Our creator, the audio manager needs to be notified when we close.
   AudioManagerMac* const manager_;