Remove ModelSafeWorker::work_done_or_stopped().

components/sync/engine/signal_event_on_delete.h

Index: components/sync/engine/signal_event_on_delete.h
diff --git a/components/sync/engine/signal_event_on_delete.h b/components/sync/engine/signal_event_on_delete.h
new file mode 100644
index 0000000000000000000000000000000000000000..e2a93de1da3e0637bf023be947664a95e1ad0424
--- /dev/null
+++ b/components/sync/engine/signal_event_on_delete.h
@@ -0,0 +1,38 @@
+// 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.
+
+#ifndef COMPONENTS_SYNC_ENGINE_SIGNAL_EVENT_ON_DELETE_H_

[Nicolas Zea, 2016/11/01 22:39:23]

I think it would be cleaner to define this file in components/sync/base than in
the engine.

[fdoray, 2016/11/02 15:52:05]

Done.

+#define COMPONENTS_SYNC_ENGINE_SIGNAL_EVENT_ON_DELETE_H_
+
+#include "base/macros.h"
+
+namespace base {
+class WaitableEvent;
+}
+
+namespace syncer {
+
+// An object which signals a WaitableEvent when it is deleted. Used to wait for
+// a task to run or be abandonned.
+class SignalEventOnDelete {

[Nicolas Zea, 2016/11/01 22:39:23]

I wonder if it would make more sense to rename this ScopedEventSignal or
something like that (following the Scoped* naming pattern)

[fdoray, 2016/11/02 15:52:05]

Done.

+ public:
+  // |event| is signaled in the destructor.
+  explicit SignalEventOnDelete(base::WaitableEvent* event);
+
+  // This SignalEventOnDelete instance will signal |other|'s event in its
+  // destructor. |other| will not signal anything in its destructor.
+  SignalEventOnDelete(SignalEventOnDelete&& other);
+  SignalEventOnDelete& operator=(SignalEventOnDelete&& other);
+
+  ~SignalEventOnDelete();
+
+ private:
+  base::WaitableEvent* event_;
+
+  DISALLOW_COPY_AND_ASSIGN(SignalEventOnDelete);
+};
+
+}  // namespace syncer
+
+#endif  // COMPONENTS_SYNC_ENGINE_SIGNAL_EVENT_ON_DELETE_H_