idl_parser: Add support for the record<K, V> WebIDL type.

tools/idl_parser/test_parser/exception_web.idl

 /* Copyright (c) 2013 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. */
 
 /* Test Exception productions
 
 Run with --test to generate an AST and verify that all comments accurately
 reflect the state of the Nodes.
 
 BUILD Type(Name)
@@ skipping 30 matching lines @@
  */
 exception MyExcInherit : Foo {};
 
 /* ERROR Unexpected keyword "exception" after keyword "partial". */
 partial exception MyExcPartial { };
 
 /* TREE
  *Exception(MyExcBig)
  *  ExceptionField(MyString)
  *    Type()
- *      PrimitiveType(DOMString)
+ *      StringType(DOMString)
  *  Error(Unexpected "=" after identifier "ErrorSetLong".)
  *  ExceptionField(MyLong)
  *    Type()
  *      PrimitiveType(long)
  */
 exception MyExcBig {
   DOMString MyString;
   unsigned long long ErrorSetLong = 123;
   long MyLong;
 };
 
 
 /* ERROR Unexpected "{" after keyword "exception". */
 exception {
   DOMString? setString = null;
 };
 
 
 /* ERROR Unexpected identifier "NoColon" after identifier "ForParent". */
 exception ForParent NoColon {
   DOMString? setString = null;
 };
 
 /* TREE
  *Exception(MyExcConst)
  *  Const(setString)
- *    PrimitiveType(DOMString)
+ *    StringType(DOMString)
  *    Value(NULL)
  */
 exception MyExcConst {
   const DOMString? setString = null;
 };