[Devtools][Regression] Fixed network film strip sometimes errored

third_party/WebKit/Source/devtools/front_end/network/NetworkPanel.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Anthony Ricaud <rik@webkit.org>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 33 matching lines @@
 
     /** @type {?PerfUI.FilmStripView} */
     this._filmStripView = null;
     /** @type {?Network.NetworkPanel.FilmStripRecorder} */
     this._filmStripRecorder = null;
 
     this._panelToolbar = new UI.Toolbar('', this.element);
     this._filterBar = new UI.FilterBar('networkPanel', true);
     this._filterBar.show(this.element);
 
+    this._filmStripPlaceholderElement = this.element.createChild('div');
+
     // Create top overview component.
     this._overviewPane = new PerfUI.TimelineOverviewPane('network');
     this._overviewPane.addEventListener(
         PerfUI.TimelineOverviewPane.Events.WindowChanged, this._onWindowChanged.bind(this));
     this._overviewPane.element.id = 'network-overview-panel';
     this._networkOverview = new Network.NetworkOverview();
     this._overviewPane.setOverviewControls([this._networkOverview]);
+    this._overviewPlaceholderElement = this.element.createChild('div');
+
     this._calculator = new Network.NetworkTransferTimeCalculator();
 
     this._splitWidget = new UI.SplitWidget(true, false, 'networkPanelSplitViewState');
     this._splitWidget.hideMain();
 
     this._splitWidget.show(this.element);
 
     this._progressBarContainer = createElement('div');
 
     this._searchableView = new UI.SearchableView(this);
@@ skipping 218 matching lines @@
     delete this._pendingStopTimer;
   }
 
   _toggleLargerRequests() {
     this._updateUI();
   }
 
   _toggleShowOverview() {
     var toggled = this._networkLogShowOverviewSetting.get();
     if (toggled)
-      this._overviewPane.show(this.element, this._splitWidget.element);
+      this._overviewPane.show(this._overviewPlaceholderElement);
     else
       this._overviewPane.detach();
     this.doResize();
   }
 
   _toggleRecordFilmStrip() {
     var toggled = this._networkRecordFilmStripSetting.get();
     if (toggled && !this._filmStripRecorder) {
       this._filmStripView = new PerfUI.FilmStripView();
       this._filmStripView.setMode(PerfUI.FilmStripView.Modes.FrameBased);
       this._filmStripView.element.classList.add('network-film-strip');
       this._filmStripRecorder =
           new Network.NetworkPanel.FilmStripRecorder(this._networkLogView.timeCalculator(), this._filmStripView);
-      this._filmStripView.show(this.element, this._overviewPane.element);
+      this._filmStripView.show(this._filmStripPlaceholderElement);
       this._filmStripView.addEventListener(PerfUI.FilmStripView.Events.FrameSelected, this._onFilmFrameSelected, this);
       this._filmStripView.addEventListener(PerfUI.FilmStripView.Events.FrameEnter, this._onFilmFrameEnter, this);
       this._filmStripView.addEventListener(PerfUI.FilmStripView.Events.FrameExit, this._onFilmFrameExit, this);
       this._resetFilmStripView();
     }
 
     if (!toggled && this._filmStripRecorder) {
       this._filmStripView.detach();
       this._filmStripView = null;
       this._filmStripRecorder = null;
@@ skipping 392 matching lines @@
    * @param {string} actionId
    * @return {boolean}
    */
   handleAction(context, actionId) {
     var panel = UI.context.flavor(Network.NetworkPanel);
     console.assert(panel && panel instanceof Network.NetworkPanel);
     panel._toggleRecording();
     return true;
   }
 };