title: android webview full screen not call onShowCustomView
body: <p>according to the hint of this :</p>
  
  <p>For full screen support, implementations of <code>WebChromeClient.onShowCustomView(android.view.View,android.webkit.WebChromeClient.CustomViewCallback)</code> and <code>WebChromeClient.onHideCustomView()</code> are required.</p>
  
  <p>i implementations this two function, and for most video,it work well, but in some cases, such as this link : </p>
  
  <p><a href="http://v.163.com/paike/V8H1BIE6U/VAG52A1KT.html" rel="nofollow">http://v.163.com/paike/V8H1BIE6U/VAG52A1KT.html</a></p>
  
  <p>when i pressed the full screen control, <code>onShowCustomView</code> didn't called ,
  i couldn't find out why, anyone who knows about this will be appricated.</p>