Fix Timers in isolates in dart2js.

lib/compiler/implementation/lib/isolate_patch.dart

Index: lib/compiler/implementation/lib/isolate_patch.dart
diff --git a/lib/compiler/implementation/lib/isolate_patch.dart b/lib/compiler/implementation/lib/isolate_patch.dart
index 033384b591e5c4f116748c8290a638306199899f..76fe2d0bc6cfa09a7b71f45e5e709afe7a47fb81 100644
--- a/lib/compiler/implementation/lib/isolate_patch.dart
+++ b/lib/compiler/implementation/lib/isolate_patch.dart
@@ -563,6 +563,12 @@ class _IsolateNatives {
     _fillStatics(_globalState.currentContext);
     _lazyPort = new ReceivePort();
     replyTo.send(_SPAWNED_SIGNAL, port.toSendPort());
+    
+    if (_window != null)  {
+      _globalState.currentContext.eval(
+          () => _setTimerFactoryClosure(_timerFactory));
+    }
+
     topLevel();
   }