Pepper: Add support for multicast in PPB_UDPSocket API

ppapi/api/private/ppb_udp_socket_private.idl

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * This file defines the <code>PPB_UDPSocket_Private</code> interface.
  */
 
 label Chrome {
   M17 = 0.2,
   M19 = 0.3,
   M23 = 0.4
 };
 
 [assert_size(4)]
 enum PP_UDPSocketFeature_Private {
   // Allow the socket to share the local address to which socket will
   // be bound with other processes. Value's type should be
   // PP_VARTYPE_BOOL.
   PP_UDPSOCKETFEATURE_PRIVATE_ADDRESS_REUSE = 0,
 
   // Allow sending and receiving packets sent to and from broadcast
   // 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.
+  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.
+  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.
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_IF = 4,
+
+  // Join a multicast group and start receiving packets. Value's type should be
+  // PP_VARTYPE_RESOURCE.
+  PP_UDPSOCKETFEATURE_PRIVATE_MULTICAST_JOIN = 5,
+
+  // Leave a multicast group previously joined. Value's type should be
+  // PP_VARTYPE_RESOURCE.
+  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 {
   /**
    * Creates a UDP socket resource.
    */
   PP_Resource Create([in] PP_Instance instance_id);
 
   /**
    * Determines if a given resource is a UDP socket.
@@ skipping 49 matching lines @@
    */
   int32_t SendTo([in] PP_Resource udp_socket,
                  [in] str_t buffer,
                  [in] int32_t num_bytes,
                  [in] PP_NetAddress_Private addr,
                  [in] PP_CompletionCallback callback);
 
   /* Cancels all pending reads and writes, and closes the socket. */
   void Close([in] PP_Resource udp_socket);
 };