Move invokeOn to InstanceMirror.

dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart

Index: dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart b/dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
index 9627509be72ec5ca22974810f3fd67e4f524aabc..86e10e04a3785f771cbbc34ddc9eca03482bf31e 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
@@ -117,7 +117,7 @@ class JSInvocationMirror implements Invocation {
     return map;
   }
 
-  invokeOn(Object object) {
+  _invokeOn(Object object) {
     var interceptor = getInterceptor(object);
     var receiver = object;
     var name = _internalName;
@@ -134,6 +134,11 @@ class JSInvocationMirror implements Invocation {
     }
     return JS("var", "#[#].apply(#, #)", receiver, name, receiver, arguments);
   }
+
+  /// This method is called by [InstanceMirror.delegate].
+  static invokeFromMirror(JSInvocationMirror invocation, victim) {
+    return invocation._invokeOn(victim);
+  }
 }
 
 class Primitives {