[ios] Allow using ipc on iOS via GN.

ipc/BUILD.gn

 # 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.
 
 import("//build/config/nacl/config.gni")
 import("//testing/test.gni")
 import("//tools/ipc_fuzzer/ipc_fuzzer.gni")
 
-assert(!is_ios)
-
 component("ipc") {
   sources = [
     "attachment_broker.cc",
     "attachment_broker.h",
     "attachment_broker_messages.h",
     "attachment_broker_privileged.cc",
     "attachment_broker_privileged.h",
     "attachment_broker_privileged_mac.cc",
     "attachment_broker_privileged_mac.h",
     "attachment_broker_privileged_win.cc",
@@ skipping 93 matching lines @@
       "ipc_channel_posix.cc",
       "unix_domain_socket_util.cc",
     ]
   } else {
     sources -= [
       "ipc_channel_nacl.cc",
       "ipc_channel_nacl.h",
     ]
   }
 
-  if (is_win || is_ios || is_nacl_nonsfi) {
+  if (is_win || is_nacl_nonsfi) {
     sources -= [ "unix_domain_socket_util.cc" ]
   }
 
   defines = [ "IPC_IMPLEMENTATION" ]
 
   public_deps = [
     ":param_traits",
   ]
   deps = [
     "//base",
@@ skipping 116 matching lines @@
   ]
   public_deps = [
     ":ipc",
   ]
   deps = [
     "//base",
     "//base/test:test_support",
     "//testing/gtest",
   ]
 }