Add embedder::AsyncWait()

mojo/edk/mojo_edk_system_impl.gypi

 # Copyright (c) 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.
 
 # The dictionary here is defined for use by the "mojo_system_impl" and
 # "mojo_system_impl_win64" targets in mojo/edk/mojo_edk.gyp. It's defined in
 # this .gypi file so the sections aren't duplicated.
 {
   'defines': [
     'MOJO_SYSTEM_IMPL_IMPLEMENTATION',
@@ skipping 24 matching lines @@
     'embedder/platform_shared_buffer.h',
     'embedder/platform_support.h',
     'embedder/scoped_platform_handle.h',
     'embedder/simple_platform_shared_buffer.cc',
     'embedder/simple_platform_shared_buffer.h',
     'embedder/simple_platform_shared_buffer_android.cc',
     'embedder/simple_platform_shared_buffer_posix.cc',
     'embedder/simple_platform_shared_buffer_win.cc',
     'embedder/simple_platform_support.cc',
     'embedder/simple_platform_support.h',
+    'system/async_waiter.cc',
+    'system/async_waiter.h',
     'system/awakable.h',
     'system/awakable_list.cc',
     'system/awakable_list.h',
     'system/channel.cc',
     'system/channel.h',
     'system/channel_endpoint.cc',
     'system/channel_endpoint.h',
     'system/channel_endpoint_client.h',
     'system/channel_endpoint_id.cc',
     'system/channel_endpoint_id.h',
@@ skipping 60 matching lines @@
     # component as non-test-only code. In the static build, this code
     # should hopefully be dead-stripped.
     'embedder/test_embedder.cc',
     'embedder/test_embedder.h',
   ],
   'all_dependent_settings': {
     # Ensures that dependent projects import the core functions on Windows.
     'defines': ['MOJO_USE_SYSTEM_IMPL'],
   },
 }