Plumb the handle signals state out of Waiter::Wait().

mojo/edk/system/message_pipe_test_utils.cc

 // 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.
 
 #include "mojo/edk/system/message_pipe_test_utils.h"
 
 #include <utility>
 
 #include "mojo/edk/embedder/simple_platform_support.h"
 #include "mojo/edk/platform/thread_utils.h"
@@ skipping 18 matching lines @@
   Waiter waiter;
   waiter.Init();
 
   MojoResult add_result =
       mp->AddAwakable(0, &waiter, signals, false, 0, signals_state);
   if (add_result != MOJO_RESULT_OK) {
     return (add_result == MOJO_RESULT_ALREADY_EXISTS) ? MOJO_RESULT_OK
                                                       : add_result;
   }
 
-  MojoResult wait_result = waiter.Wait(MOJO_DEADLINE_INDEFINITE, nullptr);
+  MojoResult wait_result =
+      waiter.Wait(MOJO_DEADLINE_INDEFINITE, nullptr, nullptr);
   mp->RemoveAwakable(0, &waiter, signals_state);
   return wait_result;
 }
 
 ChannelThread::ChannelThread(embedder::PlatformSupport* platform_support)
     : platform_support_(platform_support),
       test_io_thread_(TestIOThread::StartMode::MANUAL) {}
 
 ChannelThread::~ChannelThread() {
   Stop();
@@ skipping 58 matching lines @@
 }
 
 void MultiprocessMessagePipeTestBase::Init(RefPtr<ChannelEndpoint>&& ep) {
   channel_thread_.Start(helper_.server_platform_handle.Pass(), std::move(ep));
 }
 #endif  // !defined(OS_IOS)
 
 }  // namespace test
 }  // namespace system
 }  // namespace mojo