DevTools: Use proper target when processing worker thread events.

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 756 matching lines @@
             this._statusPane.hide();
             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(this._model.target(), this._model.inspectedTargetEvents(), this._model.sessionId() || "");
+        this._frameModel.addTraceEvents(WebInspector.targetManager.mainTarget(), this._model.inspectedTargetEvents(), this._model.sessionId() || "");
 
         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());
@@ skipping 293 matching lines @@
         if (event.name === WebInspector.TimelineModel.RecordType.Paint || event.name === WebInspector.TimelineModel.RecordType.RasterTask)
             this._showEventInPaintProfiler(event);
     },
 
     /**
      * @param {!WebInspector.TracingModel.Event} event
      * @param {boolean=} isCloseable
      */
     _showEventInPaintProfiler: function(event, isCloseable)
     {
-        var target = this._model.target();
+        var target = this._model.targetByEvent(event);

[caseq, 2016/07/19 22:48:58]

I think it should be fine to use main target here, since we won't really depend
on the inspected page state here in case of loaded timeline.

[alph, 2016/07/19 23:10:29]

Done.

         if (!target)
             return;
         var paintProfilerView = this._paintProfilerView();
         var hasProfileData = paintProfilerView.setEvent(target, event);
         if (!hasProfileData)
             return;
         if (!this._detailsView.hasTab(WebInspector.TimelinePanel.DetailsTab.PaintProfiler))
             this._detailsView.appendTab(WebInspector.TimelinePanel.DetailsTab.PaintProfiler, WebInspector.UIString("Paint Profiler"), paintProfilerView, undefined, undefined, isCloseable);
     },
 
@@ skipping 935 matching lines @@
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
         this._targets.remove(target, true);
     },
 
     __proto__: WebInspector.Object.prototype
 }