Remove the Value class names from the global namespace.

base/values.h

 // Copyright (c) 2012 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.
 
 // This file specifies a recursive data storage class called Value intended for
 // storing settings and other persistable data.
 //
 // A Value represents something that can be stored in JSON or passed to/from
 // JavaScript. As such, it is NOT a generalized variant type, since only the
 // types supported by JavaScript/JSON are supported.
@@ skipping 13 matching lines @@
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 
-// This file declares "using base::Value", etc. at the bottom, so that
-// current code can use these classes without the base namespace. In
-// new code, please always use base::Value, etc. or add your own
-// "using" declaration.
-// http://crbug.com/88666
 namespace base {
 
 class DictionaryValue;
 class FundamentalValue;
 class ListValue;
 class StringValue;
 class Value;
 
 typedef std::vector<Value*> ValueVector;
 typedef std::map<std::string, Value*> ValueMap;
@@ skipping 472 matching lines @@
   return out << static_cast<const Value&>(value);
 }
 
 BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
                                             const ListValue& value) {
   return out << static_cast<const Value&>(value);
 }
 
 }  // namespace base
 
-// http://crbug.com/88666
-using base::DictionaryValue;
-using base::ListValue;
-using base::StringValue;
-using base::Value;
-
 #endif  // BASE_VALUES_H_