Redesign the copresence audio handlers.

components/copresence/public/copresence_constants.h

Index: components/copresence/public/copresence_constants.h
diff --git a/components/copresence/public/copresence_constants.h b/components/copresence/public/copresence_constants.h
index 1c2499d7e5cb11d2b27e93b2a6f5f797384ad4ee..07c38cf0bcca34fe10d168d36fdf504c9a148b7d 100644
--- a/components/copresence/public/copresence_constants.h
+++ b/components/copresence/public/copresence_constants.h
@@ -27,6 +27,17 @@ extern const float kDefaultCarrierFrequency;
 extern const int kDefaultChannels;
 extern const media::ChannelLayout kDefaultChannelLayout;
 
+// These constants are used from everywhere.
+// Particularly, these are used to index the directive lists in the
+// audio manager, so do not change these enums without changing
+// audio_directive_list.[h|cc].
+enum AudioType {
+  AUDIBLE = 0,
+  INAUDIBLE = 1,
+  BOTH = 2,
+  AUDIO_TYPE_UNKNOWN = 3,
+};
+
 }  // namespace copresence
 
 #endif  // COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_CONSTANTS_