Extract Awakable from Waiter

mojo/edk/system/message_pipe_test_utils.cc

Index: mojo/edk/system/message_pipe_test_utils.cc
diff --git a/mojo/edk/system/message_pipe_test_utils.cc b/mojo/edk/system/message_pipe_test_utils.cc
index e5df26da48d6d939c142872dbf09d008af5f3f17..e88ffd5216fd358468b2025749f8cb8866f47068 100644
--- a/mojo/edk/system/message_pipe_test_utils.cc
+++ b/mojo/edk/system/message_pipe_test_utils.cc
@@ -21,14 +21,15 @@ MojoResult WaitIfNecessary(scoped_refptr<MessagePipe> mp,
   Waiter waiter;
   waiter.Init();
 
-  MojoResult add_result = mp->AddWaiter(0, &waiter, signals, 0, signals_state);
+  MojoResult add_result =
+      mp->AddAwakable(0, &waiter, signals, 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);
-  mp->RemoveWaiter(0, &waiter, signals_state);
+  mp->RemoveAwakable(0, &waiter, signals_state);
   return wait_result;
 }