IDL compiler: simplify type conversion in Event Constructor

Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp

Index: Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
diff --git a/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp b/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
index f088fa8e1fe4a3a1a3e47909ee121905e77cf124..49559e8e74b3e2577a795208ab3158446fca1d69 100644
--- a/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
+++ b/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
@@ -205,17 +205,17 @@ bool initializeTestInterfaceEventConstructor(TestInterfaceEventConstructorInit&
     if (!initializeEvent(eventInit, options, exceptionState, forEventName.isEmpty() ? String("TestInterfaceEventConstructor") : forEventName))
         return false;
 
-    if (!options.convert(conversionContext, "initializedByEventConstructorReadonlyStringAttribute", eventInit.initializedByEventConstructorReadonlyStringAttribute))
+    if (!options.convert(conversionContext.setConversionType("DOMString", false), "initializedByEventConstructorReadonlyStringAttribute", eventInit.initializedByEventConstructorReadonlyStringAttribute))
         return false;
-    if (options.convert(conversionContext, "deprecatedInitializedByEventConstructorReadonlyStringAttribute", eventInit.deprecatedInitializedByEventConstructorReadonlyStringAttribute)) {
+    if (options.convert(conversionContext.setConversionType("DOMString", false), "deprecatedInitializedByEventConstructorReadonlyStringAttribute", eventInit.deprecatedInitializedByEventConstructorReadonlyStringAttribute)) {
         if (options.hasProperty("deprecatedInitializedByEventConstructorReadonlyStringAttribute"))
             UseCounter::countDeprecation(activeExecutionContext(), UseCounter::initializedByEventConstructorReadonlyStringAttribute);
     } else {
         return false;
     }
-    if (!options.convert(conversionContext, "implementedAsInitializedByEventConstructorReadonlyStringAttribute", eventInit.implementedAsName))
+    if (!options.convert(conversionContext.setConversionType("DOMString", false), "implementedAsInitializedByEventConstructorReadonlyStringAttribute", eventInit.implementedAsName))
         return false;
-    if (options.convert(conversionContext, "deprecatedImplementedAsInitializedByEventConstructorReadonlyStringAttribute", eventInit.deprecatedImplementedAsName)) {
+    if (options.convert(conversionContext.setConversionType("DOMString", false), "deprecatedImplementedAsInitializedByEventConstructorReadonlyStringAttribute", eventInit.deprecatedImplementedAsName)) {
         if (options.hasProperty("deprecatedImplementedAsInitializedByEventConstructorReadonlyStringAttribute"))
             UseCounter::countDeprecation(activeExecutionContext(), UseCounter::initializedByEventConstructorReadonlyStringAttribute);
     } else {