Remove redundant timeline API

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index 8d58c705399c799434a8ec8b6568f7efae798621..05e09c9d277ac7e0dcd265bb3d52b55419f6c386 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -840,9 +840,11 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
     result = Dart_RunLoop();
     CHECK_RESULT(result);
 
-    if (isolate_data->load_async_id >= 0) {
-      Dart_TimelineAsyncEnd("LoadScript", isolate_data->load_async_id);
-    }
+    Dart_TimelineEvent("LoadScript",
+                       Dart_TimelineGetMicros(),
+                       Dart_GetMainPortId(),
+                       Dart_Timeline_Event_Async_End,
+                       0, NULL, NULL);
 
     result = DartUtils::SetupIOLibrary(script_uri);
     CHECK_RESULT(result);