Report V8 execution termination in a worker as an error.

Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp

Index: Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp
diff --git a/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp b/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp
index cc5c0f280ca834099fc088a24f199e84308fca6d..8ea0c122b7f28305eac18755d7dc0e84080ed901 100644
--- a/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp
+++ b/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp
@@ -192,6 +192,8 @@ void ServiceWorkerGlobalScope::dispatchExtendableEvent(PassRefPtrWillBeRawPtr<Ev
 
     observer->willDispatchEvent();
     dispatchEvent(event);
+    if (thread()->terminated())
+        m_hadErrorInTopLevelEventHandler = true;
     observer->didDispatchEvent(m_hadErrorInTopLevelEventHandler);
 }