DevTools: only allow status bar items in status bars.

Source/devtools/front_end/promises/PromisePane.js

 // Copyright 2014 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.VBox}
  */
 WebInspector.PromisePane = function()
 {
     WebInspector.VBox.call(this);
     this.registerRequiredCSS("promises/promisePane.css");
     this.element.classList.add("promises");
 
-    var statusBar = this.element.createChild("div", "panel-status-bar");
+    var statusBar = new WebInspector.StatusBar(this.element);
     this._recordButton = new WebInspector.StatusBarButton(WebInspector.UIString("Record Promises"), "record-profile-status-bar-item");
     this._recordButton.addEventListener("click", this._recordButtonClicked.bind(this));
-    statusBar.appendChild(this._recordButton.element);
+    statusBar.appendStatusBarItem(this._recordButton);
     var clearButton = new WebInspector.StatusBarButton(WebInspector.UIString("Clear"), "clear-status-bar-item");
     clearButton.addEventListener("click", this._clearButtonClicked.bind(this));
-    statusBar.appendChild(clearButton.element);
+    statusBar.appendStatusBarItem(clearButton);
     this._refreshButton = new WebInspector.StatusBarButton(WebInspector.UIString("Refresh"), "refresh-storage-status-bar-item");
     this._refreshButton.addEventListener("click", this._refreshButtonClicked.bind(this));
     this._refreshButton.setEnabled(false);
-    statusBar.appendChild(this._refreshButton.element);
+    statusBar.appendStatusBarItem(this._refreshButton);
     this._liveCheckbox = new WebInspector.StatusBarCheckbox(WebInspector.UIString("Live"));
     this._liveCheckbox.element.title = WebInspector.UIString("Live Recording");
     this._liveCheckbox.inputElement.disabled = true;
-    statusBar.appendChild(this._liveCheckbox.element);
+    statusBar.appendStatusBarItem(this._liveCheckbox);
 
     this._dataGridContainer = new WebInspector.VBox();
     this._dataGridContainer.show(this.element);
     var columns = [
         { id: "location", title: WebInspector.UIString("Location"), disclosure: true },
         { id: "status", title: WebInspector.UIString("Status") },
         { id: "tts", title: WebInspector.UIString("Time to settle") }
     ];
     this._dataGrid = new WebInspector.DataGrid(columns, undefined, undefined, undefined, this._onContextMenu.bind(this));
     this._dataGrid.show(this._dataGridContainer.element);
@@ skipping 151 matching lines @@
                                                           undefined,
                                                           undefined,
                                                           [promise]);
             this._target.consoleModel.addMessage(message);
             WebInspector.console.show();
         }
     },
 
     __proto__: WebInspector.VBox.prototype
 }