Cast audio only policy enforcement support.

extensions/common/api/cast_channel.idl

Index: extensions/common/api/cast_channel.idl
diff --git a/extensions/common/api/cast_channel.idl b/extensions/common/api/cast_channel.idl
index 57a3abdeabec55efc4d43fb0f8443c9e29939093..b0153f1e2808590f07658f0c7f29888d2ee07cb9 100644
--- a/extensions/common/api/cast_channel.idl
+++ b/extensions/common/api/cast_channel.idl
@@ -73,6 +73,9 @@ namespace cast.channel {
 
     // The authentication method required for the channel.
     ChannelAuthType auth;
+
+    // If set, a bit mask describing capability of the cast device.

[mark a. foltz, 2015/01/12 22:01:57]

A more self documenting API would accept an array of capability enums and
internally convert it to a bitmask for the protocol.  The downside is that we
would need to convert the IDL generated enum (which will be numbered 0 ... N-1)
to the bit shifted values internally.  I can see it either way.

If you stay with the bitmask, then please add a pointer to the canonical
definition of the values.

[vadimgo, 2015/01/13 00:08:27]

Now refer to the mask type in the comment.

+    long? capabilities;
   };
 
   // Describes the state of a channel to a Cast receiver.