sync: Gracefully handle very early shutdown

sync/internal_api/public/base/cancelation_observer.cc

Index: sync/internal_api/public/base/cancelation_observer.cc
diff --git a/sync/internal_api/public/base/cancelation_observer.cc b/sync/internal_api/public/base/cancelation_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fab9f7e407d778993f437d713fdce45a8e8d1723
--- /dev/null
+++ b/sync/internal_api/public/base/cancelation_observer.cc
@@ -0,0 +1,13 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.

[tim (not reviewing), 2013/09/06 21:47:34]

earth-shattering nit: remove the (c), per
https://groups.google.com/a/chromium.org/forum/#!searchin/chromium-dev/Copyri...

[rlarocque, 2013/09/06 22:42:53]

Fixed here and in three other files.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sync/internal_api/public/base/cancelation_observer.h"
+
+namespace syncer {
+
+CancelationObserver::CancelationObserver() {}
+
+CancelationObserver::~CancelationObserver() {}
+
+}  // namespace syncer