Timeline: do not imply event.thread.target is the main target

Source/devtools/front_end/timeline/TimelinePanel.js

Index: Source/devtools/front_end/timeline/TimelinePanel.js
diff --git a/Source/devtools/front_end/timeline/TimelinePanel.js b/Source/devtools/front_end/timeline/TimelinePanel.js
index de243fa4f2387d826ce13df20225ab87f9548cd0..a8e427b9b7bd88ae16147c213413970954fa162d 100644
--- a/Source/devtools/front_end/timeline/TimelinePanel.js
+++ b/Source/devtools/front_end/timeline/TimelinePanel.js
@@ -223,7 +223,7 @@ WebInspector.TimelinePanel.prototype = {
     _frameModel: function()
     {
         if (!this._lazyFrameModel) {
-            var tracingFrameModel = new WebInspector.TracingTimelineFrameModel();
+            var tracingFrameModel = new WebInspector.TracingTimelineFrameModel(this._model.target());
             tracingFrameModel.addTraceEvents(this._model.inspectedTargetEvents(), this._tracingModel.sessionId() || "");
             this._lazyFrameModel = tracingFrameModel;
         }
@@ -994,7 +994,8 @@ WebInspector.TimelinePanel.prototype = {
      */
     _showEventInPaintProfiler: function(event, isCloseable)
     {
-        if (!event.picture)
+        var target = this._model.target();
+        if (!event.picture || !target)
             return;
         var paintProfilerView = this._paintProfilerView();
         if (!this._detailsView.hasTab(WebInspector.TimelinePanel.DetailsTab.PaintProfiler))
@@ -1005,7 +1006,7 @@ WebInspector.TimelinePanel.prototype = {
         {
             if (!result || !result["skp64"])
                 return;
-            paintProfilerView.setPicture(event.thread.target(), result["skp64"]);
+            paintProfilerView.setPicture(target, result["skp64"]);
         }
     },