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

mojo/edk/system/mock_simple_dispatcher.cc

 // Copyright 2016 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/mock_simple_dispatcher.h"
 
 #include "base/logging.h"
 #include "mojo/edk/util/thread_annotations.h"
 
 using mojo::util::MakeRefCounted;
 using mojo::util::MutexLocker;
 using mojo::util::RefPtr;
 
 namespace mojo {
 namespace system {
 namespace test {
 
 void MockSimpleDispatcher::SetSatisfiedSignals(
     MojoHandleSignals new_satisfied_signals) {
   MutexLocker locker(&mutex());
 
   // Any new signals that are set should be satisfiable.
   CHECK_EQ(new_satisfied_signals & ~state_.satisfied_signals,
            new_satisfied_signals & ~state_.satisfied_signals &
                state_.satisfiable_signals);
 
   if (new_satisfied_signals == state_.satisfied_signals)
     return;
 
+  HandleSignalsState old_state = state_;
   state_.satisfied_signals = new_satisfied_signals;
-  HandleSignalsStateChangedNoLock();
+  OnHandleSignalsStateChangeNoLock(old_state, state_);
 }
 
 void MockSimpleDispatcher::SetSatisfiableSignals(
     MojoHandleSignals new_satisfiable_signals) {
   MutexLocker locker(&mutex());
 
   // Satisfied implies satisfiable.
   CHECK_EQ(new_satisfiable_signals & state_.satisfied_signals,
            state_.satisfied_signals);
 
   if (new_satisfiable_signals == state_.satisfiable_signals)
     return;
 
+  HandleSignalsState old_state = state_;
   state_.satisfiable_signals = new_satisfiable_signals;
-  HandleSignalsStateChangedNoLock();
+  OnHandleSignalsStateChangeNoLock(old_state, state_);
 }
 
 Dispatcher::Type MockSimpleDispatcher::GetType() const {
   return Type::UNKNOWN;
 }
 
 bool MockSimpleDispatcher::SupportsEntrypointClass(
     EntrypointClass entrypoint_class) const {
   return (entrypoint_class == EntrypointClass::NONE);
 }
@@ skipping 24 matching lines @@
 
 HandleSignalsState MockSimpleDispatcher::GetHandleSignalsStateImplNoLock()
     const {
   mutex().AssertHeld();
   return state_;
 }
 
 }  // namespace test
 }  // namespace system
 }  // namespace mojo