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

components/prefs/default_pref_store.h

Index: components/prefs/default_pref_store.h
diff --git a/components/prefs/default_pref_store.h b/components/prefs/default_pref_store.h
index 2e338899beacbbea6070110de1e3f56198184672..af7306da5b4ea3a475aab1742ed946a5f3b30bc3 100644
--- a/components/prefs/default_pref_store.h
+++ b/components/prefs/default_pref_store.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_
-#define COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_
+#ifndef BASE_PREFS_DEFAULT_PREF_STORE_H_
+#define BASE_PREFS_DEFAULT_PREF_STORE_H_
 
 #include <string>
 
@@ -15,7 +15,7 @@
 #include "components/prefs/pref_value_map.h"
 
 // Used within a PrefRegistry to keep track of default preference values.
-class COMPONENTS_PREFS_EXPORT DefaultPrefStore : public PrefStore {
+class BASE_PREFS_EXPORT DefaultPrefStore : public PrefStore {
  public:
   typedef PrefValueMap::const_iterator const_iterator;
 
@@ -50,4 +50,4 @@
   DISALLOW_COPY_AND_ASSIGN(DefaultPrefStore);
 };
 
-#endif  // COMPONENTS_PREFS_DEFAULT_PREF_STORE_H_
+#endif  // BASE_PREFS_DEFAULT_PREF_STORE_H_