Issue #4692, #3595 - Stop sleeping in the implementation of `SetTimeout`

src/JsEngine.cpp

Index: src/JsEngine.cpp
===================================================================
--- a/src/JsEngine.cpp
+++ b/src/JsEngine.cpp
@@ -22,6 +22,7 @@
 #include "JsEngineInternal.h"
 #include "JsEngineTransition.h"
 #include "JsError.h"
+#include "Timeout.h"
 #include "Utils.h"
 #include "WebRequestJsObject.h"
 
@@ -377,11 +378,13 @@
 {
   // The present version of the scheduler only does immediate and single-use
   // It does not, however, detach threads like the legacy thread behavior did.
-  scheduler.Run(Task(this, std::move(body)));
+  scheduler.Run(std::forward<std::shared_ptr<TaskFunctionInterface>>(body),
+    shared_from_this());
 }
 
 void JsEngineInternal::WaitForQuietScheduler()
 {
+  scheduler.ShutDown();
   scheduler.JoinAll();
 }