Pepper: Add support for multicast in PPB_UDPSocket API

ppapi/cpp/udp_socket.h

 // Copyright 2013 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.
 
 #ifndef PPAPI_CPP_UDP_SOCKET_H_
 #define PPAPI_CPP_UDP_SOCKET_H_
 
 #include "ppapi/c/ppb_udp_socket.h"
 #include "ppapi/cpp/net_address.h"
 #include "ppapi/cpp/pass_ref.h"
@@ skipping 138 matching lines @@
   ///
   /// @param[in] name The option to set.
   /// @param[in] value The option value to set.
   /// @param[in] callback A <code>CompletionCallback</code> to be called upon
   /// completion.
   ///
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
   int32_t SetOption(PP_UDPSocket_Option name,
                     const Var& value,
                     const CompletionCallback& callback);
+
+  /// Joins the multicast group with address specified by <code>group</code>
+  /// parameter, which is expected to be a <code>NetAddress</code> object.
+  ///
+  /// @param[in] group A <code>NetAddress</code> corresponding to the network
+  /// address of the multicast group.
+  /// @param[in] callback A <code>CompletionCallback</code> to be called upon
+  /// completion.
+  ///
+  /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
+  int32_t JoinGroup(const NetAddress& group,
+                    const CompletionCallback callback);
+
+  /// Leaves the multicast group with address specified by <code>group</code>
+  /// parameter, which is expected to be a <code>NetAddress</code> object.
+  ///
+  /// @param[in] group A <code>NetAddress</code> corresponding to the network
+  /// address of the multicast group.
+  /// @param[in] callback A <code>CompletionCallback</code> to be called upon
+  /// completion.
+  ///
+  /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
+  int32_t LeaveGroup(const NetAddress& group,
+                     const CompletionCallback callback);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_UDP_SOCKET_H_