DevTools: Use proper target when processing worker thread events.

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

Index: third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js b/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
index d567d30be2f1cdd11ed018ecab218be3c76bfecc..269bb7ed6f52698ef5e72568c6cca14a8052e50e 100644
--- a/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
+++ b/third_party/WebKit/Source/devtools/front_end/timeline/TimelinePanel.js
@@ -774,7 +774,7 @@ WebInspector.TimelinePanel.prototype = {
             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();
@@ -1088,7 +1088,7 @@ WebInspector.TimelinePanel.prototype = {
      */
     _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();