Add TCP socket mojo interfaces

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

 // Copyright 2014 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.
 
 import "mojo/services/public/interfaces/network/cookie_store.mojom"
+import "mojo/services/public/interfaces/network/net_address.mojom"
+import "mojo/services/public/interfaces/network/network_error.mojom"
+import "mojo/services/public/interfaces/network/tcp_bound_socket.mojom"
+import "mojo/services/public/interfaces/network/tcp_client_socket.mojom"
 import "mojo/services/public/interfaces/network/url_loader.mojom"
 import "mojo/services/public/interfaces/network/web_socket.mojom"
 
 module mojo {
 
 interface NetworkService {
   CreateURLLoader(URLLoader&? loader);
 
   GetCookieStore(CookieStore&? cookie_store);
 
   CreateWebSocket(WebSocket& socket);
 
-  // TODO(darin): Add other methods here.
+  // Creates a TCP socket bound to a given local address. This bound socket

[darin (slow to review), 2014/10/02 05:14:59]

not that this needs to happen now, but i think it'll make sense to have two
separate NetworkService-type interfaces. One is a high level, potentially origin
sensitive / origin bound, network service. This would have HTTP, WebSockets,
Cookie configuration, etc. The other is a low-level network service that HTTP
and WebSockets could be based on. I think TCP, UDP, DNS, proxy config should all
be part of such a lower level network service interface.

+  // can be used for creating a client or server socket on that local address.
+  //
+  // If you want to create a client socket to connect to a server and are in
+  // the common case where you don't care about the local address it's bound
+  // to, use CreateTCPClientSocket.
+  //
+  // The local address can specify 0 for the port to specify that the OS should
+  // pick an available port for the given address, or it can pass 0 for the
+  // address and port for the OS to pick both the local address and port. In
+  // all success cases, the resulting local address will be passed to the
+  // callback as bound_to.
+  CreateTCPBoundSocket(NetAddress local_address,
+                       TCPBoundSocket& bound_socket)
+      => (NetworkError result, NetAddress? bound_to);
+
+  // Creates a client socket connected to the given remote address. A local
+  // address and port will be allocated for the connection and passed to the
+  // callback on success.
+  //
+  // If you want control over the local address and port, instead use
+  // CreateTCPBoundSocket.
+  CreateTCPClientSocket(NetAddress remote_address,
+                        handle<data_pipe_consumer> send_stream,
+                        handle<data_pipe_producer> receive_stream,
+                        TCPClientSocket& client_socket)
+      => (NetworkError result,
+          NetAddress? local_address);
 };
 
 }