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

components/prefs/value_map_pref_store.h

Index: components/prefs/value_map_pref_store.h
diff --git a/components/prefs/value_map_pref_store.h b/components/prefs/value_map_pref_store.h
index bddc64196b77845d8b01edbb7b0914f6951f9008..517d07ef738b8f5f1f3d8e709c7351e2bae560d6 100644
--- a/components/prefs/value_map_pref_store.h
+++ b/components/prefs/value_map_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_VALUE_MAP_PREF_STORE_H_
-#define COMPONENTS_PREFS_VALUE_MAP_PREF_STORE_H_
+#ifndef BASE_PREFS_VALUE_MAP_PREF_STORE_H_
+#define BASE_PREFS_VALUE_MAP_PREF_STORE_H_
 
 #include <stdint.h>
 
@@ -18,7 +18,7 @@
 
 // A basic PrefStore implementation that uses a simple name-value map for
 // storing the preference values.
-class COMPONENTS_PREFS_EXPORT ValueMapPrefStore : public WriteablePrefStore {
+class BASE_PREFS_EXPORT ValueMapPrefStore : public WriteablePrefStore {
  public:
   ValueMapPrefStore();
 
@@ -54,4 +54,4 @@
   DISALLOW_COPY_AND_ASSIGN(ValueMapPrefStore);
 };
 
-#endif  // COMPONENTS_PREFS_VALUE_MAP_PREF_STORE_H_
+#endif  // BASE_PREFS_VALUE_MAP_PREF_STORE_H_