Clean up perftesthelper.js style

tools/perf/page_sets/tough_animation_cases/resources/perftesthelper.js

-// Copyright 2014 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.
-(function(){
-'use strict';
-
-if (window.PerfTestHelper) {
-  return;
-}
-window.PerfTestHelper = {};
-
-var randomSeed = 3384413;
-window.PerfTestHelper.random = function() {
-    var temp = randomSeed;
-    // Robert Jenkins' 32 bit integer hash function.
-    temp = ((temp + 0x7ed55d16) + (temp << 12))  & 0xffffffff;
-    temp = ((temp ^ 0xc761c23c) ^ (temp >>> 19)) & 0xffffffff;
-    temp = ((temp + 0x165667b1) + (temp << 5))   & 0xffffffff;
-    temp = ((temp + 0xd3a2646c) ^ (temp << 9))   & 0xffffffff;
-    temp = ((temp + 0xfd7046c5) + (temp << 3))   & 0xffffffff;
-    temp = ((temp ^ 0xb55a4f09) ^ (temp >>> 16)) & 0xffffffff;
-    randomSeed = temp;
-    return (randomSeed & 0xfffffff) / 0x10000000;
-};
-
-window.PerfTestHelper.getParameter = function(parameter) {
-    var match = new RegExp(parameter + '=([^&]*)').exec(window.location.search);
-    if (match) {
-        return match[1];
-    }
-    return null;
-}
-
-window.PerfTestHelper.getN = function(defaultN) {
-    var match = PerfTestHelper.getParameter('N');
-    if (match) {
-        var n = Number(match);
-        if (isNaN(n)) {
-            throw 'Invalid N value: ' + match;
-        }
-        return n;
-    }
-    if (typeof defaultN === 'undefined') {
-        throw 'Default N value required';
-    }
-    return defaultN;
-};
-
-window.PerfTestHelper.signalReady = function() {
-    requestAnimationFrame(function() {
-        // FIXME: We must wait at least two frames before
-        // measuring to allow the GC to clean up the
-        // previous test.
-        requestAnimationFrame(function() {
-            window.measurementReady = true;
-        });
-    });
-};
-
-})();