Remove old dead perf dashboard pages and js

perf/dashboard/ui/endure_js/dom_utils.js

-/*
-  Copyright (c) 2012 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.
-*/
-
-/**
- * @fileoverview Collection of functions which operate on DOM.
- */
-
-var domUtils = window['domUtils'] || {};
-
-/**
- * Returns pageX and pageY of the given element.
- *
- * @param {Element} element An element of which the top-left position is to be
- *     returned in the coordinate system of the document page.
- * @return {Object} A point object which has {@code x} and {@code y} fields.
- */
-domUtils.pageXY = function(element) {
-  var x = 0, y = 0;
-  for (; element; element = element.offsetParent) {
-    x += element.offsetLeft;
-    y += element.offsetTop;
-  }
-  return {'x': x, 'y': y};
-};
-
-/**
- * Returns pageX and pageY of the given event.
- *
- * @param {Event} event An event of which the position is to be returned in
- *     the coordinate system of the document page.
- * @return {Object} A point object which has {@code x} and {@code y} fields.
- */
-domUtils.pageXYOfEvent = function(event) {
-  return (event.pageX != null && event.pageY != null) ?
-      {'x': event.pageX, 'y': event.pageY} :
-      {'x': event.clientX + document.body.scrollLeft +
-            document.documentElement.scrollLeft,
-       'y': event.clientY + document.body.scrollTop +
-            document.documentElement.scrollTop};
-};