Add chrome://slow for enabling performance tracing for feedback reports.

chrome/browser/resources/chromeos/slow.js

+// Copyright (c) 2013 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('options', function() {
+  function Slow() {
+  }
+  cr.addSingletonGetter(Slow);
+
+  Slow.prototype = {
+    initialized_: false
+  };
+
+  Slow.initialize = function() {
+    $('slow-disable').addEventListener('click', function(event) {
+      Slow.disableTracing();
+    });
+    $('slow-enable').addEventListener('click', function(event) {
+      Slow.enableTracing();
+    });
+    this.initialized_ = true;
+  };
+
+  Slow.disableTracing = function() {
+    chrome.send('disableTracing');
+  };
+
+  Slow.enableTracing = function() {
+    chrome.send('enableTracing');
+  };
+
+  Slow.tracingPrefChanged = function(enabled) {
+    $('slow-disable').hidden = !enabled;
+    $('slow-enable').hidden = enabled;
+  };
+
+  // Export
+  return {
+    Slow: Slow
+  };
+});
+
+function load() {
+  options.Slow.initialize();
+    chrome.send('loadComplete');
+}
+
+document.addEventListener('DOMContentLoaded', load);