DevTools: migrate sidebar pane's titleElement to use Toolbar.

Source/devtools/front_end/sources/XHRBreakpointsSidebarPane.js

 // Copyright (c) 2015 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.
 
 /**
  * @constructor
  * @extends {WebInspector.BreakpointsSidebarPaneBase}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.XHRBreakpointsSidebarPane = function()
 {
     WebInspector.BreakpointsSidebarPaneBase.call(this, WebInspector.UIString("XHR Breakpoints"));
     this._xhrBreakpointsSetting = WebInspector.settings.createLocalSetting("xhrBreakpoints", []);
 
     /** @type {!Map.<string, !Element>} */
     this._breakpointElements = new Map();
 
-    var addButton = this.titleElement.createChild("button", "pane-title-button add");
-    addButton.title = WebInspector.UIString("Add XHR breakpoint");
-    addButton.addEventListener("click", this._addButtonClicked.bind(this), false);
+    var addButton = new WebInspector.ToolbarButton(WebInspector.UIString("Add breakpoint"), "add-toolbar-item");
+    addButton.addEventListener("click", this._addButtonClicked.bind(this));
+    this.toolbar().appendToolbarItem(addButton);
 
     this.emptyElement.addEventListener("contextmenu", this._emptyElementContextMenu.bind(this), true);
 
     WebInspector.targetManager.observeTargets(this);
 }
 
 WebInspector.XHRBreakpointsSidebarPane.prototype = {
     /**
      * @override
      * @param {!WebInspector.Target} target
@@ skipping 61 matching lines @@
 
         if (this._breakpointElements.has(url))
             return;
 
         var element = createElement("li");
         element._url = url;
         element.addEventListener("contextmenu", this._contextMenu.bind(this, url), true);
 
         var title = url ? WebInspector.UIString("URL contains \"%s\"", url) : WebInspector.UIString("Any XHR");
         var label = createCheckboxLabel(title, enabled);
-        label.classList.add("checkbox-elem");
         element.appendChild(label);
         label.checkboxElement.addEventListener("click", this._checkboxClicked.bind(this, url), false);
         element._checkboxElement = label.checkboxElement;
 
         label.textElement.classList.add("cursor-auto");
         label.textElement.addEventListener("dblclick", this._labelClicked.bind(this, url), false);
 
         var currentElement = /** @type {?Element} */ (this.listElement.firstChild);
         while (currentElement) {
             if (currentElement._url && currentElement._url < element._url)
@@ skipping 134 matching lines @@
         var breakpoints = this._xhrBreakpointsSetting.get();
         for (var i = 0; i < breakpoints.length; ++i) {
             var breakpoint = breakpoints[i];
             if (breakpoint && typeof breakpoint.url === "string")
                 this._setBreakpoint(breakpoint.url, breakpoint.enabled, target);
         }
     },
 
     __proto__: WebInspector.BreakpointsSidebarPaneBase.prototype
 }