[Sync] Rename syncable_prefs to sync_preferences.

components/syncable_prefs/synced_pref_observer.h

Index: components/syncable_prefs/synced_pref_observer.h
diff --git a/components/syncable_prefs/synced_pref_observer.h b/components/syncable_prefs/synced_pref_observer.h
deleted file mode 100644
index b8f387dee7ad87a419ebbf8dd92e7d559f12d42d..0000000000000000000000000000000000000000
--- a/components/syncable_prefs/synced_pref_observer.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// 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.
-
-#ifndef COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_OBSERVER_H_
-#define COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_OBSERVER_H_
-
-#include <string>
-
-namespace syncable_prefs {
-
-class SyncedPrefObserver {
- public:
-  virtual void OnSyncedPrefChanged(const std::string& path, bool from_sync) = 0;
-};
-
-}  // namespace syncable_prefs
-
-#endif  // COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_OBSERVER_H_