Update from https://crrev.com/304121

sandbox/linux/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.
 
 import("//build/config/features.gni")
 
 declare_args() {
   compile_suid_client = is_linux
 
   compile_credentials = is_linux
@@ skipping 211 matching lines @@
 component("sandbox_services") {
   sources = [
     "services/init_process_reaper.cc",
     "services/init_process_reaper.h",
     "services/scoped_process.cc",
     "services/scoped_process.h",
     "services/thread_helpers.cc",
     "services/thread_helpers.h",
     "services/yama.h",
     "services/yama.cc",
+    "syscall_broker/broker_channel.cc",
+    "syscall_broker/broker_channel.h",
     "syscall_broker/broker_client.cc",
     "syscall_broker/broker_client.h",
     "syscall_broker/broker_common.h",
     "syscall_broker/broker_host.cc",
     "syscall_broker/broker_host.h",
     "syscall_broker/broker_policy.cc",
     "syscall_broker/broker_policy.h",
     "syscall_broker/broker_process.cc",
     "syscall_broker/broker_process.h",
   ]
@@ skipping 83 matching lines @@
   #      'type': 'none',
   #      'variables': {
   #        'test_suite_name': 'sandbox_linux_jni_unittests',
   #      },
   #      'dependencies': [
   #        'sandbox_linux_jni_unittests',
   #      ],
   #      'includes': [ '../../build/apk_test.gypi' ],
   #      }
 }