Move invokeOn to InstanceMirror.

dart/tests/language/invocation_mirror_invoke_on_test.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.
 
+import "dart:mirrors" show reflect;
 import "package:expect/expect.dart";
 
-// Testing Invocation.invokeOn method; test of issue 7227.
+// Testing InstanceMirror.delegate method; test of issue 7227.
 
 var reachedSetX = 0;
 var reachedGetX = 0;
 var reachedM = 0;
 
 class A {
 
   set x(val) {
     reachedSetX = val;
   }
 
   get x {
     reachedGetX = 1;
   }
 
   m() { reachedM = 1; }
 }
 
 class B {
   final a = new A();
-  noSuchMethod(mirror) => mirror.invokeOn(a);
+  noSuchMethod(mirror) => reflect(a).delegate(mirror);
 }
 
 main () {
   var b = new B();
   b.x = 10;
   Expect.equals(10, reachedSetX);
   b.x;
   Expect.equals(1, reachedGetX);
   b.m();
   Expect.equals(1, reachedM);
 }