Remove old tracing code now that it has moved to third_party.

chrome/browser/resources/tracing/measuring_stick.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.
-
-cr.define('tracing', function() {
-  /**
-   * Uses an embedded iframe to measure provided elements without forcing layout
-   * on the main document.
-   * @constructor
-   * @extends {Object}
-   */
-  function MeasuringStick() {
-    var iframe = document.createElement('iframe');
-    iframe.style.cssText = 'width:100%;height:0;border:0;visibility:hidden';
-    document.body.appendChild(iframe);
-    this._doc = iframe.contentDocument;
-    this._window = iframe.contentWindow;
-    this._doc.body.style.cssText = 'padding:0;margin:0;overflow:hidden';
-
-    var stylesheets = document.querySelectorAll('link[rel=stylesheet]');
-    for (var i = 0; i < stylesheets.length; i++) {
-      var stylesheet = stylesheets[i];
-      var link = this._doc.createElement('link');
-      link.rel = 'stylesheet';
-      link.href = stylesheet.href;
-      this._doc.head.appendChild(link);
-    }
-  }
-
-  MeasuringStick.prototype = {
-    __proto__: Object.prototype,
-
-    /**
-     * Measures the provided element without forcing layout on the main
-     * document.
-     */
-    measure: function(element) {
-      this._doc.body.appendChild(element);
-      var style = this._window.getComputedStyle(element);
-      var width = parseInt(style.width, 10);
-      var height = parseInt(style.height, 10);
-      this._doc.body.removeChild(element);
-      return { width: width, height: height };
-    }
-  };
-
-  return {
-    MeasuringStick: MeasuringStick
-  };
-});