Support for [Clamp] and [EnforceRange] to IDL dictionary.

Source/core/testing/InternalDictionary.idl

 // Copyright 2014 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.
 
 enum InternalEnum { "foo", "bar", "baz" };
 
 dictionary InternalDictionary {
     long longMember;
+    [Clamp] long longMemberWithClamp;
     long longMemberWithDefault = 42;
     long? longOrNullMember;
     long? longOrNullMemberWithDefault = null;
     boolean booleanMember;
     double doubleMember;
     DOMString stringMember;
     DOMString stringMemberWithDefault = "defaultStringValue";
     sequence<DOMString> stringSequenceMember;
     sequence<DOMString>? stringSequenceOrNullMember;
     InternalEnum enumMember;
     InternalEnum enumMemberWithDefault = "foo";
     InternalEnum? enumOrNullMember;
     Element elementMember;
     Element? elementOrNullMember;
     object objectMember;
     object? objectOrNullMemberWithDefault = null;
 };