Mojo UDP: add a client-side wrapper which handles the client<->server buffering

mojo/services/public/interfaces/network/udp_socket.mojom

Index: mojo/services/public/interfaces/network/udp_socket.mojom
diff --git a/mojo/services/public/interfaces/network/udp_socket.mojom b/mojo/services/public/interfaces/network/udp_socket.mojom
index 0816ace76115d84fa1b53b124f5e08ee0710d130..f26cd09cb387a648666f6ca06d741a9e79205dde 100644
--- a/mojo/services/public/interfaces/network/udp_socket.mojom
+++ b/mojo/services/public/interfaces/network/udp_socket.mojom
@@ -54,7 +54,7 @@ interface UDPSocket {
   // Notifies that the client is ready to accept |number| of datagrams.
   // Correspondingly, OnReceived() of the UDPSocketClient interface will be
   // called |number| times (errors also count), unless the connection is closed
-  // before that. The socket must be bound.
+  // before that.
   //
   // It is allowed to call this method again before the previous request is
   // completely satisfied. For example: