title: Android WebView with embedded YouTube video has no fullscreen button
body: <p>I'm trying to put a little embedded youtube video in my app. The user needs to be able to fullscreen the video, but the webview's youtube player has no fullscreen button! Whhhaa…? I've searched around and found no solution. BTW, using the Google YouTube API is NOT an option. I have a workaround (video thumbnail which opens a fullscreen WebView when clicked), but it would be a lot simpler/more elegant if the webview would handle this for me.</p>
  
  <p>Here's how I'm loading the youtube video</p>
  
  <pre><code> String htmlString = "&lt;html&gt;&lt;body style='margin:0px auto; padding:0px; width: 100%;'&gt;&lt;script type='text/javascript' src='http://m.youtube.com/iframe_api'&gt;&lt;/script&gt;&lt;div style=\"padding-bottom: 56.25%;position: relative;\"&gt;&lt;iframe allowfullscreen='allowfullscreen' id='playerId' type='text/html' style=\"width: 100%; height: 100%; position: absolute;\" width=\"560\" height=\"315\" src='http://www.youtube.com/embed/IwfUnkBfdZ4?enablejsapi=1&amp;rel=0&amp;playsinline=0&amp;autoplay=0' frameborder='0'&gt;&lt;/div&gt;&lt;/body&gt;&lt;/html&gt;";
          if (youtubeWebView == null){
              youtubeWebView = ButterKnife.findById(view, R.id.youtubeWebview);
          }
          youtubeWebView.getSettings().setJavaScriptEnabled(true);
          youtubeWebView.getSettings().setLoadWithOverviewMode(true);
          youtubeWebView.loadData(htmlString, "text/html", null);
  </code></pre>