[Sync] Move events files around a bit.

components/sync/driver/protocol_event_observer.h

Index: components/sync/driver/protocol_event_observer.h
diff --git a/components/sync/driver/protocol_event_observer.h b/components/sync/driver/protocol_event_observer.h
deleted file mode 100644
index 651069aca08e21140341b4a958022cbe8005f685..0000000000000000000000000000000000000000
--- a/components/sync/driver/protocol_event_observer.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2014 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_DRIVER_PROTOCOL_EVENT_OBSERVER_H_
-#define COMPONENTS_SYNC_DRIVER_PROTOCOL_EVENT_OBSERVER_H_
-
-namespace syncer {
-
-class ProtocolEvent;
-
-class ProtocolEventObserver {
- public:
-  ProtocolEventObserver();
-  virtual ~ProtocolEventObserver();
-
-  virtual void OnProtocolEvent(const ProtocolEvent& event) = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_SYNC_DRIVER_PROTOCOL_EVENT_OBSERVER_H_