Pass more detailed audio hardware configuration information to the renderer

media/base/channel_layout.h

Index: media/base/channel_layout.h
===================================================================
--- media/base/channel_layout.h	(revision 187053)
+++ media/base/channel_layout.h	(working copy)
@@ -96,6 +96,9 @@
   // Front L, Front R, Front C, Side L, Side R, Rear C, Back L, Back R.
   CHANNEL_LAYOUT_OCTAGONAL = 28,
 
+  // Channels are not explicitly mapped to speakers.
+  CHANNEL_LAYOUT_DISCRETE = 29,
+
   // Total number of layouts.
   CHANNEL_LAYOUT_MAX  // Must always be last!
 };
@@ -123,6 +126,10 @@
 // Returns the number of channels in a given ChannelLayout.
 MEDIA_EXPORT int ChannelLayoutToChannelCount(ChannelLayout layout);
 
+// Given the number of channels, return the best layout,
+// or return CHANNEL_LAYOUT_UNSUPPORTED if there is no good match.
+MEDIA_EXPORT ChannelLayout GuessChannelLayout(int channels);
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_CHANNEL_LAYOUT_H_