Support correct factory syntax in the VM as decribed in the spec.

tests/language/src/TypeVariableScopeTest.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
+// VMOptions=--enable_type_checks
 
 // Test that type variables aren't in scope of static methods and factories.
 
 class Foo<T> {
   // T is not in scope for a static method.
   static
   Foo<T> /// 00: compile-time error
   m(
     Foo<T> /// 01: compile-time error
     f) {
     I<T> x; /// 02: compile-time error
   }
 
   // T is not in scope for a static method.
-  factory I(
+  factory I<X>(
             I<T> /// 03: compile-time error
             i) {
     I<T> x; /// 04: compile-time error
   }
 
   // T is not in scope for a static field.
   static Foo<T> f1; /// 05: compile-time error
 
   static
   Foo<T> /// 06: compile-time error
   get f() { return null; }
 
   static void set f(
                     Foo<T> /// 07: compile-time error
                     value) {}
 }
 
-interface I<X> factory Foo<X> {
+interface I<X> factory Foo<T> {
   I(I<X> i);
 }
 
 main() {
   Foo.m(null);
   new I(null);
 }