Add trace links to chrome://inspect (if chrome://inspect?tracing is used)

chrome/browser/resources/inspect/inspect.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.
 
 var MIN_VERSION_TAB_CLOSE = 25;
 var MIN_VERSION_TARGET_ID = 26;
 var MIN_VERSION_NEW_TAB = 29;
 var MIN_VERSION_TAB_ACTIVATE = 30;
 
 var queryParamsObject = {};
@@ skipping 311 matching lines @@
               handler();
           }.bind(null, openHandler), true);
 
           var newPageButton = document.createElement('button');
           newPageButton.textContent = 'Open';
           newPage.appendChild(newPageButton);
           newPageButton.addEventListener('click', openHandler, true);
 
           browserHeader.appendChild(newPage);
         }
 

[pfeldman, 2014/06/16 17:11:15]

Is there a reason to not do something like below (and not touch the backend
part?)

var browserInspector;
var browserInspectorTitle;

if ('trace' in queryParamsObject || 'tracing' in queryParamsObject) {
  browserInspector = 'chrome://tracing';
  browserInspectorTitle = 'trace';
else {
  browserInspector = queryParamsObject['browser-inspector'];
  browserInspectorTitle = 'trace';
}

if (browserInspector) {
  ...

         if (queryParamsObject['browser-inspector']) {
           var link = document.createElement('span');
           link.classList.add('action');
           link.setAttribute('tabindex', 1);
           link.textContent = 'inspect';
           browserHeader.appendChild(link);
           link.addEventListener(
               'click',
               sendCommand.bind(null, 'inspect-browser', browser.source,
                   browser.id, queryParamsObject['browser-inspector']), false);
         }
 
+        if ('trace' in queryParamsObject || 'tracing' in queryParamsObject) {
+          var link = document.createElement('span');
+          link.classList.add('action');
+          link.setAttribute('tabindex', 1);
+          link.textContent = 'trace';
+          browserHeader.appendChild(link);
+          link.addEventListener(
+              'click',
+              sendCommand.bind(null, 'trace-browser', browser.source,
+                  browser.id), false);
+        }
+
         pageList = document.createElement('div');
         pageList.className = 'list pages';
         browserSection.appendChild(pageList);
       }
 
       if (incompatibleVersion || alreadyDisplayed(browserSection, browser))
         continue;
 
       pageList.textContent = '';
       for (var p = 0; p < browser.pages.length; p++) {
@@ skipping 571 matching lines @@
     deviceSection.querySelector('.device-ports').textContent = '';
   }
 
   Array.prototype.forEach.call(
       document.querySelectorAll('.device'), clearPorts);
 }
 
 document.addEventListener('DOMContentLoaded', onload);
 
 window.addEventListener('hashchange', onHashChange);