Make the root zone's schduleMicrotask and create[Periodic]Timer bind the callback.

sdk/lib/async/zone.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.
 
 part of dart.async;
 
 typedef dynamic ZoneCallback();
 typedef dynamic ZoneUnaryCallback(arg);
 typedef dynamic ZoneBinaryCallback(arg1, arg2);
 
@@ skipping 341 matching lines @@
    *      ZoneCallback registered = registerBinaryCallback(f);
    *      if (runGuarded) {
    *        return (arg1, arg2) => this.runBinaryGuarded(registered, arg);
    *      }
    *      return (arg1, arg2) => thin.runBinary(registered, arg1, arg2);
    */
   ZoneBinaryCallback bindBinaryCallback(
       f(arg1, arg2), { bool runGuarded: true });
 
   /**
-   * Runs [f] asynchronously.
+   * Runs [f] asynchronously in this zone.
    */
   void scheduleMicrotask(void f());
 
   /**
    * Creates a Timer where the callback is executed in this zone.
    */
   Timer createTimer(Duration duration, void callback());
 
   /**
    * Creates a periodic Timer where the callback is executed in this zone.
@@ skipping 352 matching lines @@
     Zone self, ZoneDelegate parent, Zone zone, f(arg)) {
   return f;
 }
 
 ZoneBinaryCallback _rootRegisterBinaryCallback(
     Zone self, ZoneDelegate parent, Zone zone, f(arg1, arg2)) {
   return f;
 }
 
 void _rootScheduleMicrotask(Zone self, ZoneDelegate parent, Zone zone, f()) {
+  if (Zone.ROOT != zone) {
+    f = zone.bindCallback(f);
+  }
   _scheduleAsyncCallback(f);
 }
 
 Timer _rootCreateTimer(Zone self, ZoneDelegate parent, Zone zone,
                        Duration duration, void callback()) {
+  if (Zone.ROOT != zone) {
+    callback = zone.bindCallback(callback);
+  }
   return _createTimer(duration, callback);
 }
 
 Timer _rootCreatePeriodicTimer(
     Zone self, ZoneDelegate parent, Zone zone,
     Duration duration, void callback(Timer timer)) {
+  if (Zone.ROOT != zone) {
+    callback = zone.bindUnaryCallback(callback);
+  }
   return _createPeriodicTimer(duration, callback);
+}
 
-}
 void _rootPrint(Zone self, ZoneDelegate parent, Zone zone, String line) {
   printToConsole(line);
 }
 
 void _printToZone(String line) {
   Zone.current.print(line);
 }
 
 Zone _rootFork(Zone self, ZoneDelegate parent, Zone zone,
                ZoneSpecification specification,
@@ skipping 149 matching lines @@
                                    handleUncaughtError: errorHandler);
   }
   Zone zone = Zone.current.fork(specification: zoneSpecification,
                                 zoneValues: zoneValues);
   if (onError != null) {
     return zone.runGuarded(body);
   } else {
     return zone.run(body);
   }
 }