Use Mojo pipes to signal sync IPC events

mojo/edk/system/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/nacl/config.gni")
 import("//testing/test.gni")
 import("../../../mojo/public/tools/bindings/mojom.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 94 matching lines @@
       "mach_port_relay.cc",
       "mach_port_relay.h",
     ]
   }
 
   if (is_nacl && !is_nacl_nonsfi) {
     sources -= [
       "broker_host_posix.cc",
       "broker_posix.cc",
       "channel_posix.cc",
+      "remote_message_pipe_bootstrap.cc",
     ]
   }
 
   allow_circular_includes_from = [ "//mojo/edk/embedder" ]
 }
 
 group("tests") {
   testonly = true
   deps = [
     ":mojo_system_unittests",
@@ skipping 76 matching lines @@
       ":test_utils",
       "//base",
       "//base/test:test_support",
       "//mojo/edk/system",
       "//mojo/edk/test:run_all_perftests",
       "//mojo/edk/test:test_support",
       "//testing/gtest",
     ]
   }
 }