Issue 4399 - Add WebView inheritor with ad blocking

libadblockplus-android-webview/assets/css.js

+{
+   {{DEBUG}} console.log('starting injecting css rules');
+   var selectors = JSON.parse({{BRIDGE}}.getElemhideSelectors());
+   {{DEBUG}} console.log('parsed selectors: ' + selectors.length);
+   var head = document.getElementsByTagName("head")[0];
+   var style = document.createElement("style");
+   head.appendChild(style);
+   var sheet = style.sheet ? style.sheet : style.styleSheet;
+   for (var i=0; i<selectors.length; i++)
+   {
+     if (sheet.insertRule)
+     {
+       sheet.insertRule(selectors[i] + ' { display: none !important; }', 0);
+     }
+     else
+     {
+       sheet.addRule(selectors[i], 'display: none !important;', 0);
+     }
+   }
+   {{DEBUG}} console.log('finished injecting css rules');
+}