DevTools: migrate UI.ViewManager's expand icon over to UI.Icon

third_party/WebKit/Source/devtools/front_end/ui/View.js

 // Copyright 2016 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.
 /**
  * @interface
  */
 UI.View = function() {};
 
 UI.View.prototype = {
   /**
@@ skipping 446 matching lines @@
 UI.ViewManager._ExpandableContainerWidget = class extends UI.VBox {
   /**
    * @param {!UI.View} view
    */
   constructor(view) {
     super(true);
     this.element.classList.add('flex-none');
     this.registerRequiredCSS('ui/viewContainers.css');
 
     this._titleElement = createElementWithClass('div', 'expandable-view-title');
-    this._titleElement.textContent = view.title();
+    this._titleExpandIcon = UI.Icon.create('smallicon-triangle-right', 'title-expand-icon');
+    this._titleElement.appendChild(this._titleExpandIcon);
+    this._titleElement.createTextChild(view.title());
     this._titleElement.tabIndex = 0;
     this._titleElement.addEventListener('click', this._toggleExpanded.bind(this), false);
     this._titleElement.addEventListener('keydown', this._onTitleKeyDown.bind(this), false);
     this.contentElement.insertBefore(this._titleElement, this.contentElement.firstChild);
 
     this.contentElement.createChild('content');
     this._view = view;
     view[UI.ViewManager._ExpandableContainerWidget._symbol] = this;
   }
 
@@ skipping 15 matching lines @@
     return this._materializePromise;
   }
 
   /**
    * @return {!Promise}
    */
   _expand() {
     if (this._titleElement.classList.contains('expanded'))
       return this._materialize();
     this._titleElement.classList.add('expanded');
+    this._titleExpandIcon.setIconType('smallicon-triangle-down');
     return this._materialize().then(() => this._widget.show(this.element));
   }
 
   _collapse() {
     if (!this._titleElement.classList.contains('expanded'))
       return;
     this._titleElement.classList.remove('expanded');
+    this._titleExpandIcon.setIconType('smallicon-triangle-right');
     this._materialize().then(() => this._widget.detach());
   }
 
   _toggleExpanded() {
     if (this._titleElement.classList.contains('expanded'))
       this._collapse();
     else
       this._expand();
   }
 
@@ skipping 337 matching lines @@
   appendApplicableItems(locationName) {
     for (var view of this._manager._viewsForLocation(locationName))
       this.appendView(view);
   }
 };
 
 /**
  * @type {!UI.ViewManager}
  */
 UI.viewManager;