Resolve redirecting factories.

dart/lib/compiler/implementation/typechecker.dart

Index: dart/lib/compiler/implementation/typechecker.dart
diff --git a/dart/lib/compiler/implementation/typechecker.dart b/dart/lib/compiler/implementation/typechecker.dart
index 33b1dced3c9a08f531db2633816d70e59d34e2aa..909641c5830f98a789f8afe5efd9b2ecc32e6ea9 100644
--- a/dart/lib/compiler/implementation/typechecker.dart
+++ b/dart/lib/compiler/implementation/typechecker.dart
@@ -51,6 +51,8 @@ abstract class DartType {
   abstract DartType unalias(Compiler compiler);
 
   abstract bool operator ==(other);
+
+  DartType asRaw() => this;
 }
 
 class TypeVariableType implements DartType {
@@ -156,6 +158,11 @@ class InterfaceType implements DartType {
     if (!identical(element, other.element)) return false;
     return arguments == other.arguments;
   }
+
+  InterfaceType asRaw() {
+    if (arguments.isEmpty()) return this;
+    return new InterfaceType(element);
+  }
 }
 
 class FunctionType implements DartType {
@@ -753,7 +760,7 @@ class TypeCheckerVisitor implements Visitor<DartType> {
     if (node.isRedirectingFactoryBody) {
       // TODO(lrn): Typecheck the body. It must refer to the constructor
       // of a subtype.
-      return elements.getType(node);
+      return StatementType.RETURNING;
     }
 
     final expression = node.expression;