Allow access to type variables as expressions in factory constructors.

pkg/compiler/lib/src/elements/elements.dart

 // Copyright (c) 2012, 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.
 
 library elements;
 
 
 import '../constants/expressions.dart';
 import '../tree/tree.dart';
 import '../util/util.dart';
@@ skipping 472 matching lines @@
       element = closureClass.methodElement;
     }
     Element outer = element.outermostEnclosingMemberOrTopLevel;
     if (isUnresolved(outer)) return true;
     if (outer.isTopLevel) return true;
     if (outer.isGenerativeConstructor) return false;
     if (outer.isInstanceMember) return false;
     return true;
   }
 
+  static bool hasAccessToTypeVariables(Element element) {
+    Element outer = element.outermostEnclosingMemberOrTopLevel;
+    return (outer != null && outer.isFactoryConstructor) ||
+        !isInStaticContext(element);
+  }
+
   static bool isStaticOrTopLevelField(Element element) {
     return isStaticOrTopLevel(element)
            && (identical(element.kind, ElementKind.FIELD)
                || identical(element.kind, ElementKind.GETTER)
                || identical(element.kind, ElementKind.SETTER));
   }
 
   static bool isStaticOrTopLevelFunction(Element element) {
     return isStaticOrTopLevel(element)
            && (identical(element.kind, ElementKind.FUNCTION));
@@ skipping 1123 matching lines @@
   bool get isDeclaredByField;
 
   /// Returns `true` if this member is abstract.
   bool get isAbstract;
 
   /// If abstract, [implementation] points to the overridden concrete member,
   /// if any. Otherwise [implementation] points to the member itself.
   Member get implementation;
 }