Install 'get call' on Closure class.

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

 // Copyright (c) 2013, 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 _js_helper;
 
 import 'dart:_js_embedded_names' show
     GET_TYPE_FROM_NAME,
     GET_ISOLATE_TAG,
     INTERCEPTED_NAMES,
@@ skipping 1928 matching lines @@
   /**
    * Global counter to prevent reusing function code objects.
    *
    * V8 will share the underlying function code objects when the same string is
    * passed to "new Function".  Shared function code objects can lead to
    * sub-optimal performance due to polymorhism, and can be prevented by
    * ensuring the strings are different.
    */
   static int functionCounter = 0;
 
+  Closure get call => this;
+
   Closure();
 
   /**
    * Creates a new closure class for use by implicit getters associated with a
    * method.
    *
    * In other words, creates a tear-off closure.
    *
    * Called from [closureFromTearOff] as well as from reflection when tearing
    * of a method via [:getField:].
@@ skipping 1761 matching lines @@
   // This is a function that will return a helper function that does the
   // iteration of the sync*.
   //
   // Each invocation should give a helper with fresh state.
   final dynamic /* js function */ _outerHelper;
 
   SyncStarIterable(this._outerHelper);
 
   Iterator get iterator => new SyncStarIterator(JS('', '#()', _outerHelper));
 }