title: Is it possible to inject JS to Android WebView before the page is loaded?
body: <p>I need to add some properties to the window object before a page is loaded and its JS code is executed. I have a couple of reasons to do it, but one is to add support for HTML5 APIs which are not yet supported in Android WebView. If I inject the JS code in onPageLoad(), it works fine for all JS code which is executed afterwards. However I need to make a third-party page to be loaded well and it has some JS code which is executed before I inject my JS code. I checked the other questions asked here like 
  <a href="https://stackoverflow.com/questions/14064589/android-webview-inject-javascript-before-html-loaded">Android WebView Inject Javascript before html loaded</a> but they don't provide good answers. I have tried to inject JS code in onLoadResource() but it still doesn't do the trick for me.</p>
  
  <p>Any ideas?</p>