Ensure JavaScript equality when serviceWorker.register resolves to an existing worker [1/3]

Source/modules/serviceworkers/ServiceWorker.cpp

Index: Source/modules/serviceworkers/ServiceWorker.cpp
diff --git a/Source/modules/serviceworkers/ServiceWorker.cpp b/Source/modules/serviceworkers/ServiceWorker.cpp
index 5d86c5a7fe093cbe0bd36555c2f0806384e31cf4..25e449d44977d6fac532b0ad79f381041c8355ee 100644
--- a/Source/modules/serviceworkers/ServiceWorker.cpp
+++ b/Source/modules/serviceworkers/ServiceWorker.cpp
@@ -158,7 +158,8 @@ PassRefPtrWillBeRawPtr<ServiceWorker> ServiceWorker::from(ScriptPromiseResolver*
 {
     RefPtrWillBeRawPtr<ServiceWorker> serviceWorker = ServiceWorker::from(resolver->scriptState()->executionContext(), worker);
     ScriptState::Scope scope(resolver->scriptState());
-    serviceWorker->waitOnPromise(resolver->promise());
+    if (serviceWorker->m_proxyState == Initial)
+        serviceWorker->waitOnPromise(resolver->promise());
     return serviceWorker;
 }