Revert of Delete base/prefs and update callers to use components.

components/prefs/pref_filter.h

 // 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_PREFS_PREF_FILTER_H_
-#define COMPONENTS_PREFS_PREF_FILTER_H_
+#ifndef BASE_PREFS_PREF_FILTER_H_
+#define BASE_PREFS_PREF_FILTER_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/prefs/base_prefs_export.h"
 
 namespace base {
 class DictionaryValue;
 class Value;
 }  // namespace base
 
 // Filters preferences as they are loaded from disk or updated at runtime.
 // Currently supported only by JsonPrefStore.
-class COMPONENTS_PREFS_EXPORT PrefFilter {
+class BASE_PREFS_EXPORT PrefFilter {
  public:
   // A callback to be invoked when |prefs| have been read (and possibly
   // pre-modified) and are now ready to be handed back to this callback's
   // builder. |schedule_write| indicates whether a write should be immediately
   // scheduled (typically because the |prefs| were pre-modified).
   typedef base::Callback<void(scoped_ptr<base::DictionaryValue> prefs,
                               bool schedule_write)> PostFilterOnLoadCallback;
 
   virtual ~PrefFilter() {}
 
@@ skipping 13 matching lines @@
   virtual void FilterUpdate(const std::string& path) = 0;
 
   // Receives notification when the pref store is about to serialize data
   // contained in |pref_store_contents| to a string. Modifications to
   // |pref_store_contents| will be persisted to disk and also affect the
   // in-memory state.
   virtual void FilterSerializeData(
       base::DictionaryValue* pref_store_contents) = 0;
 };
 
-#endif  // COMPONENTS_PREFS_PREF_FILTER_H_
+#endif  // BASE_PREFS_PREF_FILTER_H_