Force non overlay scrollbar in Devtools/Performance for Aura Overlay Scrollbar

third_party/WebKit/Source/devtools/front_end/emulation/AdvancedApp.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 {Common.App}
  * @unrestricted
  */
 Emulation.AdvancedApp = class {
   constructor() {
     Components.dockController.addEventListener(
@@ skipping 53 matching lines @@
 
     var url = window.location.href.replace('inspector.html', 'toolbox.html');
     this._toolboxWindow = window.open(url, undefined);
   }
 
   /**
    * @param {!Document} toolboxDocument
    */
   toolboxLoaded(toolboxDocument) {
     UI.initializeUIUtils(toolboxDocument, Common.settings.createSetting('uiTheme', 'default'));
-    UI.installComponentRootStyles(/** @type {!Element} */ (toolboxDocument.body));
+    UI.installComponentRootStyles(toolboxDocument, /** @type {!Element} */ (toolboxDocument.body));

[alph, 2017/05/22 18:50:08]

You don't need a document. Please check how we do the same trick in
UI.measurePreferredSize

     UI.ContextMenu.installHandler(toolboxDocument);
     UI.Tooltip.installHandler(toolboxDocument);
 
     this._toolboxRootView = new UI.RootView();
     this._toolboxRootView.attachToDocument(toolboxDocument);
 
     this._updateDeviceModeView();
   }
 
   _updateDeviceModeView() {
@@ skipping 107 matching lines @@
  */
 Emulation.AdvancedAppProvider = class {
   /**
    * @override
    * @return {!Common.App}
    */
   createApp() {
     return Emulation.AdvancedApp._instance();
   }
 };