The Tor Browser / file revision

 "use strict";

 function parseArgs() {

   var query = window.location.search.substring(1);

   var split = query.split("&");

   var args = {}

   for (var i = 0; i < split.length; i++) {

     var pair = split[i].split("=");

     var key = pair[0];

     var value = true;

     if (pair.length >= 2) {

       eval("value = " + decodeURIComponent(pair[1]) + ";");

     }

     args[key] = value;

   }

   return args;

 }

 var gArgs = null;

 function arg(key) {

   if (gArgs === null) {

     gArgs = parseArgs();

   }

   var ret = gArgs[key];

   if (ret === undefined)

     ret = false;

   return ret;

 }

 function initGL(canvas) {

   if (arg("nogl"))

     return null;

   var gl = null;

   var withAA = arg("aa");

   var withAlpha = arg("alpha");

   var withDepth = arg("depth");

   var withPremult = arg("premult");

   var withPreserve = arg("preserve");

   var withStencil = arg("stencil");

   try {

     var argDict = {

       alpha: withAlpha,

       depth: withDepth,

       stencil: withStencil,

       antialias: withAA,

       premultipliedAlpha: withPremult,

       preserveDrawingBuffer: withPreserve,

     };

     gl = canvas.getContext("experimental-webgl", argDict);

   } catch(e) {}

   return gl;

 }

 function rAF(func) {

   var raf = window.requestAnimationFrame || window.mozRequestAnimationFrame;

   raf(func);

 }

 var MAX_WAIT_FOR_COMPOSITE_DELAY_MS = 500;

 function waitForComposite(func) {

   var isDone = false;

   var doneFunc = function () {

     if (isDone)

       return;

     isDone = true;

     func();

   };

   rAF(doneFunc);

   setTimeout(doneFunc, MAX_WAIT_FOR_COMPOSITE_DELAY_MS);

 }