Fix shake-to-reload

sky/framework/debug/shake-to-reload.sky

Index: sky/framework/debug/shake-to-reload.sky
diff --git a/sky/framework/debug/shake-to-reload.sky b/sky/framework/debug/shake-to-reload.sky
index ac0a894cc4f9ccefec0d3ddcffb70102ad9d01a6..2fc8bbac65482c07f778cbdddc8eda193ff1ce6f 100644
--- a/sky/framework/debug/shake-to-reload.sky
+++ b/sky/framework/debug/shake-to-reload.sky
@@ -9,10 +9,8 @@ class _ShakeDetector extends SensorListener {
     SensorServiceProxy sensorService = new SensorServiceProxy.unbound();
     shell.requestService(sensorService);
 
-    _stub = new SensorListenerStub.unbound()
-            ..delegate = this;
+    _stub = new SensorListenerStub.unbound()..impl = this;
     sensorService.ptr.addListener(SensorType_ACCELEROMETER, _stub);
-    _stub.listen();
   }
 
   void onAccuracyChanged(int accuracy) {