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

mojo/edk/system/channel_unittest.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/channel.h"
 
 #include <utility>
 
 #include "mojo/edk/system/channel_endpoint.h"
 #include "mojo/edk/system/channel_endpoint_id.h"
@@ skipping 54 matching lines @@
   waiter.Init();
   ASSERT_EQ(MOJO_RESULT_OK,
             mp->AddAwakable(0, &waiter, MOJO_HANDLE_SIGNAL_READABLE, false, 123,
                             nullptr));
 
   // Don't wait for the shutdown to run ...
   io_thread()->PostTaskAndWait([this]() { ShutdownChannelOnIOThread(0); });
 
   // ... since this |Wait()| should fail once the channel is shut down.
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
-            waiter.Wait(MOJO_DEADLINE_INDEFINITE, nullptr));
+            waiter.Wait(MOJO_DEADLINE_INDEFINITE, nullptr, nullptr));
   HandleSignalsState hss;
   mp->RemoveAwakable(0, &waiter, &hss);
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_PEER_CLOSED, hss.satisfied_signals);
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_PEER_CLOSED, hss.satisfiable_signals);
 
   mp->Close(0);
 
   EXPECT_TRUE(channel(0)->HasOneRef());
 }
 
@@ skipping 46 matching lines @@
     io_thread()->PostTaskAndWait([]() {});
     EXPECT_FALSE(channel(0));
   }
 }
 
 // TODO(vtl): More. ------------------------------------------------------------
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo