[DevTools] Fix 'node targets available' not appearing, but listed in Remote Devices drawer tab.

third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.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.
 /**
  * @implements {SDK.SDKModelObserver<!SDK.DebuggerModel>}
  * @implements {UI.ListDelegate<!SDK.DebuggerModel>}
  */
 Sources.ThreadsSidebarPane = class extends UI.VBox {
   constructor() {
     super(true);
     this.registerRequiredCSS('sources/threadsSidebarPane.css');
 
-    this._availableNodeTargetsElement = this.element.createChild('div', 'hidden available-node-targets');
-
     /** @type {!UI.ListControl<!SDK.DebuggerModel>} */
     this._list = new UI.ListControl(this, UI.ListMode.NonViewport);
     this.contentElement.appendChild(this._list.element);
 
+    this._availableNodeTargetsElement = this.contentElement.createChild('div', 'hidden available-node-targets');
+
     UI.context.addFlavorChangeListener(SDK.Target, this._targetFlavorChanged, this);
 
     SDK.targetManager.addModelListener(
         SDK.SubTargetsManager, SDK.SubTargetsManager.Events.AvailableNodeTargetsChanged,
         this._availableNodeTargetsChanged, this);
     this._availableNodeTargetsChanged();
 
     SDK.targetManager.observeModels(SDK.DebuggerModel, this);
   }
 
@@ skipping 134 matching lines @@
   /**
    * @param {!Common.Event} event
    */
   _targetFlavorChanged(event) {
     var target = /** @type {!SDK.Target} */ (event.data);
     var debuggerModel = target.model(SDK.DebuggerModel);
     if (debuggerModel)
       this._list.selectItem(debuggerModel);
   }
 };