Use Mojo pipes to signal sync IPC events

components/nacl/broker/BUILD.gn

 # Copyright 2016 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")
 
 # This file builds nacl64.exe, which is a 64-bit x86 Windows executable
 # used only in the 32-bit x86 Windows build.  The :broker code runs both
 # in nacl64.exe and in the 32-bit chrome executable, to launch
 # nacl64.exe and communicate with it.
@@ skipping 87 matching lines @@
       ":broker",
       ":nacl64_content",
       ":nacl64_crash_reporter_client",
       "//base",
       "//breakpad:breakpad_handler",
       "//build/win:default_exe_manifest",
       "//chrome:nacl64_exe_version",
       "//components/crash/content/app:app_breakpad_mac_win_to_be_deleted",
       "//components/nacl/loader:nacl_helper_win_64",
       "//content/public/common:static_switches",
+      "//mojo/edk/system",
       "//ppapi/proxy:ipc",
       "//sandbox",
     ]
   }
 
   # This is a tiny subset of //content built specially for nacl64.exe.
   # There are no subcomponents of //content small enough to get just
   # what nacl64.exe needs without bringing in other stuff that causes
   # problems for the build.
   source_set("nacl64_content") {
@@ skipping 37 matching lines @@
       "//chrome/installer/util:with_no_strings",
       "//components/browser_watcher:browser_watcher_client",
       "//components/flags_ui:switches",
       "//components/policy",
       "//content/public/common:static_switches",
       "//ipc",
       "//third_party/kasko:kasko_features",
     ]
   }
 }