QmlProfiler: showing children time and count in events pane

Change-Id: Ia285d1c84312e6a314fbf1c59c62b571b4c3e7d4
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/qmlprofiler/qml/Overview.js

@@ -83,6 +83,9 @@ function drawData(canvas, ctxt, region)
 
 function drawTimeBar(canvas, ctxt, region)
 {
+    if (!qmlEventList)
+        return;
+
     var width = canvas.width;
     var height = 10;
     var startTime = qmlEventList.traceStartTime();