Correctly attribute exceptions thrown inside a Worker's imported scripts.

Source/core/workers/WorkerGlobalScope.cpp

Index: Source/core/workers/WorkerGlobalScope.cpp
diff --git a/Source/core/workers/WorkerGlobalScope.cpp b/Source/core/workers/WorkerGlobalScope.cpp
index 263c9ec6874424fbc91bc06f25e66f22c844e91a..f80e1ffce1fbce92a2df89978d9e09dd0faf7832 100644
--- a/Source/core/workers/WorkerGlobalScope.cpp
+++ b/Source/core/workers/WorkerGlobalScope.cpp
@@ -214,10 +214,10 @@ void WorkerGlobalScope::importScripts(const Vector<String>& urls, ExceptionState
 
         InspectorInstrumentation::scriptImported(scriptExecutionContext(), scriptLoader->identifier(), scriptLoader->script());
 
-        ScriptValue exception;
-        m_script->evaluate(ScriptSourceCode(scriptLoader->script(), scriptLoader->responseURL()), &exception);
-        if (!exception.hasNoValue()) {
-            m_script->setException(exception);
+        RefPtr<ErrorEvent> errorEvent;
+        m_script->evaluate(ScriptSourceCode(scriptLoader->script(), scriptLoader->responseURL()), &errorEvent);
+        if (errorEvent) {
+            m_script->rethrowExceptionFromImportedScript(errorEvent.release());
             return;
         }
     }