Timeline: always create filmstrip model and share single instance of it

third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 45 matching lines @@
     if (!Runtime.experiments.isEnabled("timelineShowAllEvents")) {
         this._filters.push(WebInspector.TimelineUIUtils.visibleEventsFilter());
         this._filters.push(new WebInspector.ExcludeTopLevelFilter());
     }
 
     // Create models.
     this._tracingModelBackingStorage = new WebInspector.TempFileBackingStorage("tracing");
     this._tracingModel = new WebInspector.TracingModel(this._tracingModelBackingStorage);
     this._model = new WebInspector.TimelineModel(WebInspector.TimelineUIUtils.visibleEventsFilter());
     this._frameModel = new WebInspector.TimelineFrameModel(event => WebInspector.TimelineUIUtils.eventStyle(event).category.name);
+    this._filmStripModel = new WebInspector.FilmStripModel(this._tracingModel);
     this._irModel = new WebInspector.TimelineIRModel();
 
     this._cpuThrottlingManager = new WebInspector.CPUThrottlingManager();
 
     /** @type {!Array.<!WebInspector.TimelineModeView>} */
     this._currentViews = [];
 
     this._captureNetworkSetting = WebInspector.settings.createSetting("timelineCaptureNetwork", false);
     this._captureJSProfileSetting = WebInspector.settings.createSetting("timelineEnableJSSampling", true);
     this._captureMemorySetting = WebInspector.settings.createSetting("timelineCaptureMemory", false);
@@ skipping 462 matching lines @@
     {
         // Set up overview controls.
         this._overviewControls = [];
         this._overviewControls.push(new WebInspector.TimelineEventOverview.Responsiveness(this._model, this._frameModel));
         if (Runtime.experiments.isEnabled("inputEventsOnTimelineOverview"))
             this._overviewControls.push(new WebInspector.TimelineEventOverview.Input(this._model));
         this._overviewControls.push(new WebInspector.TimelineEventOverview.Frames(this._model, this._frameModel));
         this._overviewControls.push(new WebInspector.TimelineEventOverview.CPUActivity(this._model));
         this._overviewControls.push(new WebInspector.TimelineEventOverview.Network(this._model));
         if (this._captureFilmStripSetting.get())
-            this._overviewControls.push(new WebInspector.TimelineFilmStripOverview(this._model, this._tracingModel));
+            this._overviewControls.push(new WebInspector.TimelineFilmStripOverview(this._model, this._filmStripModel));
         if (this._captureMemorySetting.get())
             this._overviewControls.push(new WebInspector.TimelineEventOverview.Memory(this._model));
         this._overviewPane.setOverviewControls(this._overviewControls);
 
         // Set up the main view.
         this._removeAllModeViews();
         this._flameChart = new WebInspector.TimelineFlameChartView(this, this._model, this._frameModel, this._irModel, this._filters);
         this._flameChart.enableNetworkPane(this._captureNetworkSetting.get());
         this._addModeView(this._flameChart);
 
@@ skipping 117 matching lines @@
     _clear: function()
     {
         WebInspector.LineLevelProfile.instance().reset();
         this._tracingModel.reset();
         this._model.reset();
         this._showRecordingHelpMessage();
 
         this.requestWindowTimes(0, Infinity);
         delete this._selection;
         this._frameModel.reset();
+        this._filmStripModel.reset(this._tracingModel);
         this._overviewPane.reset();
         for (var i = 0; i < this._currentViews.length; ++i)
             this._currentViews[i].reset();
         for (var i = 0; i < this._overviewControls.length; ++i)
             this._overviewControls[i].reset();
         this.select(null);
-        delete this._filmStripModel;
         this._detailsSplitWidget.hideSidebar();
     },
 
     /**
      * @override
      */
     recordingStarted: function()
     {
         this._clear();
         this._setState(WebInspector.TimelinePanel.State.Recording);
@@ skipping 93 matching lines @@
             delete this._statusPane;
             this._clear();
             return;
         }
 
         if (this._statusPane)
             this._statusPane.updateStatus(WebInspector.UIString("Processing timeline\u2026"));
         this._model.setEvents(this._tracingModel, loadedFromFile);
         this._frameModel.reset();
         this._frameModel.addTraceEvents(WebInspector.targetManager.mainTarget(), this._model.inspectedTargetEvents(), this._model.sessionId() || "");
-
+        this._filmStripModel.reset(this._tracingModel);
         var groups = WebInspector.TimelineModel.AsyncEventGroup;
         var asyncEventsByGroup = this._model.mainThreadAsyncEvents();
         this._irModel.populate(asyncEventsByGroup.get(groups.input), asyncEventsByGroup.get(groups.animation));
         this._model.cpuProfiles().forEach(profile => WebInspector.LineLevelProfile.instance().appendCPUProfile(profile));
         if (this._statusPane)
             this._statusPane.hide();
         delete this._statusPane;
         this._overviewPane.reset();
         this._overviewPane.setBounds(this._model.minimumRecordTime(), this._model.maximumRecordTime());
         this._setAutoWindowTimes();
@@ skipping 211 matching lines @@
 
     _updateSelectionDetails: function()
     {
         switch (this._selection.type()) {
         case WebInspector.TimelineSelection.Type.TraceEvent:
             var event = /** @type {!WebInspector.TracingModel.Event} */ (this._selection.object());
             WebInspector.TimelineUIUtils.buildTraceEventDetails(event, this._model, this._detailsLinkifier, true, this._appendDetailsTabsForTraceEventAndShowDetails.bind(this, event));
             break;
         case WebInspector.TimelineSelection.Type.Frame:
             var frame = /** @type {!WebInspector.TimelineFrame} */ (this._selection.object());
-            if (!this._filmStripModel)
-                this._filmStripModel = new WebInspector.FilmStripModel(this._tracingModel);
+            var filmStripFrame = null;
             var screenshotTime = frame.idle ? frame.startTime : frame.endTime; // For idle frames, look at the state at the beginning of the frame.
-            var filmStripFrame = this._filmStripModel && this._filmStripModel.frameByTimestamp(screenshotTime);
+            filmStripFrame = this._filmStripModel.frameByTimestamp(screenshotTime);

[alph, 2016/09/08 00:03:07]

var ...

             if (filmStripFrame && filmStripFrame.timestamp - frame.endTime > 10)
                 filmStripFrame = null;
             this.showInDetails(WebInspector.TimelineUIUtils.generateDetailsContentForFrame(this._frameModel, frame, filmStripFrame));
             if (frame.layerTree) {
                 var layersView = this._layersView();
                 layersView.showLayerTree(frame.layerTree, frame.paints);
                 if (!this._detailsView.hasTab(WebInspector.TimelinePanel.DetailsTab.LayerViewer))
                     this._detailsView.appendTab(WebInspector.TimelinePanel.DetailsTab.LayerViewer, WebInspector.UIString("Layers"), layersView);
             }
             break;
@@ skipping 1065 matching lines @@
     _onKeyDown: function(event)
     {
         if (event.keyCode === WebInspector.KeyboardShortcut.Keys.Enter.code) {
             event.preventDefault();
             this._apply();
         }
     },
 
     __proto__: WebInspector.HBox.prototype
 }