Support general handling of type variables by substituting types into the current context.

tests/language/generic_field_mixin6_test.dart

Index: tests/language/generic_field_mixin6_test.dart
diff --git a/tests/language/checked_mode_helper.dart b/tests/language/generic_field_mixin6_test.dart
similarity index 68%
copy from tests/language/checked_mode_helper.dart
copy to tests/language/generic_field_mixin6_test.dart
index 695222da755f57d923f5d991f1902eeaa5ea670b..d4d4095da5a27177be7e5749a28905b0ebbec749 100644
--- a/tests/language/checked_mode_helper.dart
+++ b/tests/language/generic_field_mixin6_test.dart
@@ -1,11 +1,28 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2014, 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 checked_mode_helper;
+// Test that generic types in mixins are handled.
 
 import 'package:expect/expect.dart';
 
+class M<T> {
+  T field = 0; /// 01: static type warning
+}
+class A<U> {}
+class C1<V> = Object with M<V>;
+class C2 = Object with M<int>;
+class C3 = Object with M<String>;
+
+main() {
+  checkNoDynamicTypeError(() => new C1<int>());  /// 01: continued
+  checkDynamicTypeError(() => new C1<String>()); /// 01: continued
+
+  checkNoDynamicTypeError(() => new C2());       /// 01: continued
+
+  checkDynamicTypeError(() => new C3());         /// 01: continued
+}
+
 /// Returns `true` if the program is running in checked mode.
 bool inCheckedMode() {
   try {
@@ -18,16 +35,6 @@ bool inCheckedMode() {
 }
 
 /// Checks that a dynamic type error is thrown if and only if [f] is executed in
-/// checked mode and [expectTypeError] is `true`.
-void testDynamicTypeError(bool expectTypeError, f(), [String message]) {
-  if (expectTypeError) {
-    checkDynamicTypeError(f, message);
-  } else {
-    checkNoDynamicTypeError(f, message);
-  }
-}
-
-/// Checks that a dynamic type error is thrown if and only if [f] is executed in
 /// checked mode.
 void checkDynamicTypeError(f(), [String message]) {
   message = message != null ? ': $message' : '';