[DevTools] Introduce Common.List used as a backend for list controls

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');
 
+    /** @type {!UI.ListModel<!SDK.DebuggerModel>} */
+    this._items = new UI.ListModel();
     /** @type {!UI.ListControl<!SDK.DebuggerModel>} */
-    this._list = new UI.ListControl(this, UI.ListMode.NonViewport);
+    this._list = new UI.ListControl(this._items, this, UI.ListMode.NonViewport);
     this.contentElement.appendChild(this._list.element);
 
     UI.context.addFlavorChangeListener(SDK.Target, this._targetFlavorChanged, this);
     SDK.targetManager.observeModels(SDK.DebuggerModel, this);
   }
 
   /**
    * @return {boolean}
    */
   static shouldBeShown() {
@@ skipping 74 matching lines @@
       toElement.classList.add('selected');
     if (to)
       UI.context.setFlavor(SDK.Target, to.target());
   }
 
   /**
    * @override
    * @param {!SDK.DebuggerModel} debuggerModel
    */
   modelAdded(debuggerModel) {
-    this._list.pushItem(debuggerModel);
+    this._items.pushItem(debuggerModel);
     var currentTarget = UI.context.flavor(SDK.Target);
     if (currentTarget === debuggerModel.target())
       this._list.selectItem(debuggerModel);
   }
 
   /**
    * @override
    * @param {!SDK.DebuggerModel} debuggerModel
    */
   modelRemoved(debuggerModel) {
-    this._list.removeItem(debuggerModel);
+    this._items.removeItem(debuggerModel);
   }
 
   /**
    * @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);
   }
 };