update CreateFromEventPipeEventSource to support providing preloaded rundown source

Author: vaind

src/TraceEvent/TraceLog.cs

@@ -220,10 +220,20 @@ public static TraceLogEventSource CreateFromEventPipeSession(EventPipeSession se
         /// the .Log Property) which lets you get at aggregated information (Processes, threads, images loaded, and perhaps most
         /// importantly TraceEvent.CallStack() will work. Thus you can get real time stacks from events).
         /// </summary>
-        public static TraceLogEventSource CreateFromEventPipeEventSource(EventPipeEventSource source)
+        /// <param name="rundownSource">
+        /// If given, the rundownSource is used to initialize module and method information.
+        /// This only makes sense in realtime sessions when you need to resolve function names.
+        /// </param>
+        public static TraceLogEventSource CreateFromEventPipeEventSource(EventPipeEventSource source, EventPipeSession rundownSource = null)
         {
             var traceLog = new TraceLog(source);
             traceLog.rawEventSourceToConvert.AllEvents += traceLog.onAllEventPipeEventsRealTime;
+
+            if (rundownSource != null)
+            {
+                traceLog.ProcessInitialRundown(rundownSource);
+            }
+
             return traceLog.realTimeSource;
         }
 
@@ -248,6 +258,12 @@ private void ProcessInitialRundown(EventPipeSession session)
             }
         }
 
+        private void ProcessInitialRundown(EventPipeEventSource source)
+        {
+            SetupInitialRundownCallbacks(source);
+            source.Process();
+        }
+
         /// <summary>
         /// Attaches callbacks to initialize modules and methods based on the rundown events.
         /// Unlike SetupCallbacks(), these callbacks are attached before any events are processed so