Update ChannelReader to use AttachmentBroker.

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("//testing/test.gni")
 
 component("ipc") {
   sources = [
+    "attachment_broker.cc",
     "attachment_broker.h",
     "attachment_broker_messages.h",
     "attachment_broker_win.cc",
     "attachment_broker_win.h",
     "brokerable_attachment.cc",
     "brokerable_attachment.h",
     "handle_attachment_win.cc",
     "handle_attachment_win.h",
     "ipc_channel.cc",
     "ipc_channel.h",
@@ skipping 85 matching lines @@
     "//crypto:crypto",
   ]
 }
 
 # TODO(GYP): crbug.com/360936. Get this to build and run on Android.
 if (!is_android) {
   test("ipc_tests") {
     sources = [
       "attachment_broker_win_unittest.cc",
       "ipc_channel_posix_unittest.cc",
+      "ipc_channel_reader_unittest.cc",
       "ipc_channel_unittest.cc",
       "ipc_fuzzing_tests.cc",
       "ipc_message_attachment_set_posix_unittest.cc",
       "ipc_message_unittest.cc",
       "ipc_message_utils_unittest.cc",
       "ipc_send_fds_test.cc",
       "ipc_sync_channel_unittest.cc",
       "ipc_sync_message_unittest.cc",
       "ipc_sync_message_unittest.h",
       "sync_socket_unittest.cc",
@@ skipping 71 matching lines @@
     "ipc_test_sink.cc",
     "ipc_test_sink.h",
   ]
   deps = [
     ":ipc",
     "//base",
     "//base/test:test_support",
     "//testing/gtest",
   ]
 }