Remove the Value class names from the global namespace.

chrome/browser/prefs/pref_hash_calculator.cc

Index: chrome/browser/prefs/pref_hash_calculator.cc
diff --git a/chrome/browser/prefs/pref_hash_calculator.cc b/chrome/browser/prefs/pref_hash_calculator.cc
index 4a787a8a1abb699d8a3447c3a34caf3eee638bb8..e2468f86c33b3cd25da36ec795b42bd7dbc7840f 100644
--- a/chrome/browser/prefs/pref_hash_calculator.cc
+++ b/chrome/browser/prefs/pref_hash_calculator.cc
@@ -22,7 +22,7 @@ std::string ValueAsString(const base::Value* value) {
   // Dictionary values may contain empty lists and sub-dictionaries. Make a
   // deep copy with those removed to make the hash more stable.
   const base::DictionaryValue* dict_value;
-  scoped_ptr<DictionaryValue> canonical_dict_value;
+  scoped_ptr<base::DictionaryValue> canonical_dict_value;
   if (value && value->GetAsDictionary(&dict_value)) {
     canonical_dict_value.reset(dict_value->DeepCopyWithoutEmptyChildren());
     value = canonical_dict_value.get();