Pepper: Add support for multicast in PPB_UDPSocket API

ppapi/api/private/ppb_udp_socket_private.idl

Index: ppapi/api/private/ppb_udp_socket_private.idl
diff --git a/ppapi/api/private/ppb_udp_socket_private.idl b/ppapi/api/private/ppb_udp_socket_private.idl
index 9888a548e9951bc7197e608cb5d58d32153ef895..b3c4643a2ce4e80883518866b0f830b2b8fd9ca4 100644
--- a/ppapi/api/private/ppb_udp_socket_private.idl
+++ b/ppapi/api/private/ppb_udp_socket_private.idl
@@ -10,7 +10,8 @@
 label Chrome {
   M17 = 0.2,
   M19 = 0.3,
-  M23 = 0.4
+  M23 = 0.4,
+  M41 = 0.5
 };
 
 [assert_size(4)]
@@ -24,9 +25,39 @@ enum PP_UDPSocketFeature_Private {
   // addresses. Value's type should be PP_VARTYPE_BOOL.
   PP_UDPSOCKETFEATURE_PRIVATE_BROADCAST = 1,
 
+  // Whether multicast packets sent from the host to the multicast group should
+  // be looped back to the host or not. Value's type should be PP_VARTYPE_BOOL.
+  // This is only supported in version 0.5 of the API (Chrome 41) and later.
+  [version=0.5]
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_LOOP = 2,
+
+  // Set time-to-live for multicast packets, from 0 to 255. Value's type should
+  // be PP_VARTYPE_INT32.
+  // This is only supported in version 0.5 of the API (Chrome 41) and later.
+  [version=0.5]
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_TTL = 3,
+
+  // Set network interface from which the multicast packets will be sent and
+  // received. Value's type should be PP_VARTYPE_INT32.
+  // This is only supported in version 0.5 of the API (Chrome 41) and later.
+  [version=0.5]
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_IF = 4,
+
+  // Join a multicast group and start receiving packets. Value's type should be
+  // PP_VARTYPE_RESOURCE.
+  // This is only supported in version 0.5 of the API (Chrome 41) and later.
+  [version=0.5]
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_JOIN = 5,
+
+  // Leave a multicast group previously joined. Value's type should be
+  // PP_VARTYPE_RESOURCE.
+  // This is only supported in version 0.5 of the API (Chrome 41) and later.
+  [version=0.5]
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_LEAVE = 6,
+
   // Special value for counting the number of available
   // features. Should not be passed to SetSocketFeature().
-  PP_UDPSOCKETFEATURE_PRIVATE_COUNT = 2
+  PP_UDPSOCKETFEATURE_PRIVATE_COUNT = 7
 };
 
 interface PPB_UDPSocket_Private {