title: GIF display issue while using WebView(The first frame is always there)
body: <p>I have a webview and call mWebView.loadUrl("file:///android_asset/test.html");
  the content of test.html is just a IMG SRC=...
  the webview can show the animation GIF, but the issue is the first frame of the GIF is always there while the GIF is animating.</p>
  
  <p>What the problem is and how to fix?</p>