Removing canvas rendering mode switching feature

third_party/WebKit/Source/modules/canvas2d/tools/bench.js

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-var bench = (function() {
-  var rafFunc;
-  var drawFunc;
-
-  function tick() {
-    drawFunc();
-    rafFunc(tick);
-  };
-
-  function startAnimation() {
-    rafFunc = window.requestAnimationFrame ||
-              window.webkitRequestAnimationFrame ||
-              window.mozRequestAnimationFrame ||
-              window.oRequestAnimationFrame ||
-              window.msRequestAnimationFrame;
-    rafFunc(tick);
-  };
-
-  var bench = {};
-  bench.run = function(df) {
-    drawFunc = df;
-    startAnimation();
-  };
-  return bench;
-})();