Give AwakableList's wake-up method the old state in addition to the new state.

mojo/edk/system/simple_dispatcher.cc

 // Copyright 2013 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/simple_dispatcher.h"
 
 #include "base/logging.h"
 
 namespace mojo {
 namespace system {
 
-SimpleDispatcher::SimpleDispatcher() {
-}
+SimpleDispatcher::SimpleDispatcher() {}
 
-SimpleDispatcher::~SimpleDispatcher() {
-}
+SimpleDispatcher::~SimpleDispatcher() {}
 
-void SimpleDispatcher::HandleSignalsStateChangedNoLock() {
+void SimpleDispatcher::OnHandleSignalsStateChangeNoLock(
+    const HandleSignalsState& old_state,
+    const HandleSignalsState& new_state) {
   mutex().AssertHeld();
-  awakable_list_.AwakeForStateChange(GetHandleSignalsStateImplNoLock());
+  awakable_list_.OnStateChange(old_state, new_state);
 }
 
 void SimpleDispatcher::CancelAllStateNoLock() {
   mutex().AssertHeld();
   awakable_list_.CancelAll();
 }
 
 MojoResult SimpleDispatcher::AddAwakableImplNoLock(
     Awakable* awakable,
     MojoHandleSignals signals,
@@ skipping 34 matching lines @@
     uint64_t context,
     HandleSignalsState* signals_state) {
   mutex().AssertHeld();
   awakable_list_.RemoveWithContext(awakable, context);
   if (signals_state)
     *signals_state = GetHandleSignalsStateImplNoLock();
 }
 
 }  // namespace system
 }  // namespace mojo