Timeline: rearrange trace completion logic for better extensibility

third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html

Index: third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html
diff --git a/third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html b/third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html
index 02dc07ec6f3861206cd0b2d6a51c285f87e0e68e..2a2b00ebd007251b6df25c9c0cc4f06ad2720b33 100644
--- a/third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html
+++ b/third_party/WebKit/LayoutTests/inspector/tracing/trace-event-self-time.html
@@ -287,12 +287,10 @@ function test()
     var timelineController = InspectorTest.timelineController();
     timelineController._addCpuProfile(WebInspector.targetManager.mainTarget().id(), null, cpuProfile);
     timelineController.traceEventsCollected(rawTraceEvents);
-    timelineController.tracingComplete();
-    InspectorTest.addSniffer(WebInspector.panels.timeline, "loadingComplete", () => {
-        var events = InspectorTest.timelineModel().inspectedTargetEvents();
-        events.forEach(e => InspectorTest.addResult(e.name + ": " + e.startTime + " " + (e.selfTime || 0).toFixed(2) + "/" + (e.duration || 0).toFixed(2)));
-        InspectorTest.completeTest();
-    });
+    timelineController._allSourcesFinished();
+    var events = InspectorTest.timelineModel().inspectedTargetEvents();
+    events.forEach(e => InspectorTest.addResult(e.name + ": " + e.startTime + " " + (e.selfTime || 0).toFixed(2) + "/" + (e.duration || 0).toFixed(2)));
+    InspectorTest.completeTest();
 }
 
 </script>