title: Why UIActivityIndicatorView is not showing on UIWebView?
body: <p>Code:</p>
  
  <pre><code>CGPoint centerPoint = [_inner_web_view center];
  CGRect frame = CGRectMake(centerPoint.x, centerPoint.y, 100, 100);
  _activity_indicator = [[UIActivityIndicatorView alloc]
                         initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
  [_activity_indicator setFrame:frame];
  [_inner_web_view addSubview:_activity_indicator];
  </code></pre>
  
  <p>What I need is to display ActivityIndicator on UIWebView.
  Even after using [_activity_indicator startAnimating] nothing happens. :(</p>
  
  <p>Can someone help me find out WHY this happens?</p>