Restructure public side of network service.

mojo/services/network/public/cpp/BUILD.gn

 # 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.
 
-source_set("network") {
+source_set("cpp") {
   sources = [
     "udp_socket_wrapper.cc",
     "udp_socket_wrapper.h",
     "web_socket_read_queue.cc",
     "web_socket_read_queue.h",
     "web_socket_write_queue.cc",
     "web_socket_write_queue.h",
   ]
 
   deps = [
     "//base",
     "//mojo/application",
     "//mojo/common",
     "//mojo/environment:chromium",
     "//mojo/public/c/system",
     "//mojo/public/cpp/system",
-    "//mojo/services/public/interfaces/network",
+    "//mojo/services/network/public/interfaces",
   ]
 }