title: WindowManager.addView() crashes
body: <p>Here is my code :</p>
  
  <pre><code>protected window_fly (Context context) {
  
      WindowManager.LayoutParams params = new WindowManager.LayoutParams (
              WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
              WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
              PixelFormat.TRANSLUCENT ) ;
  
      params.gravity = Gravity.LEFT | Gravity.BOTTOM ;
  
      LayoutInflater layOutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE)  ;
      View in_view = layOutInflater.inflate(R.layout.in_layout, null) ;
      Toast.makeText(context, "daemon born", Toast.LENGTH_SHORT).show() ; 
      WindowManager wm = (WindowManager) context.getSystemService(context.WINDOW_SERVICE); 
      //wm.addView(in_view, params);
  }
  </code></pre>
  
  <p>all in Service context. window_fly is the constructor. If I uncomment wm.addView() and run it, app will fall. Please, tell me possible reasons of it. Sorry for poor English.</p>