Add perf tests for animations using different CSS value types

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(){

[qyearsley, 2015/02/17 17:51:40]

[Optional] You could also make this file match the style guide. The body of a
function is normally indented 2 spaces, including for function expressions.

http://www.chromium.org/developers/web-development-style-guide
https://google-styleguide.googlecode.com/svn/trunk/javascriptguide.xml

[alancutter (OOO until 2018), 2015/02/17 20:42:12]

Will do in separate patch.

 '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 = /N=(\d+)/.exec(window.location.search);
+    var match = PerfTestHelper.getParameter('N');
     if (match) {
-        return Number(match[1]);
+        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;
         });
     });
 };
 
 })();