Add support for [TreatNullAs] extended attribute for reflected attributes

Source/core/html/HTMLScriptElement.idl

Index: Source/core/html/HTMLScriptElement.idl
diff --git a/Source/core/html/HTMLScriptElement.idl b/Source/core/html/HTMLScriptElement.idl
index ef68a4dd87c2b781dc2b749780989d02e540d25f..b5b34d9a37f8517030b6afd0f9c5c753f673e987 100644
--- a/Source/core/html/HTMLScriptElement.idl
+++ b/Source/core/html/HTMLScriptElement.idl
@@ -19,13 +19,13 @@
 
 interface HTMLScriptElement : HTMLElement {
     [TreatNullAs=NullString] attribute DOMString text;
-    [Reflect=for] attribute DOMString htmlFor;
-    [Reflect] attribute DOMString event;
-    [Reflect] attribute DOMString charset;
+    [Reflect=for, TreatNullAs=NullString] attribute DOMString htmlFor;
+    [Reflect, TreatNullAs=NullString] attribute DOMString event;
+    [Reflect, TreatNullAs=NullString] attribute DOMString charset;
     attribute boolean async;
     [Reflect] attribute boolean defer;
-    [Reflect, URL] attribute DOMString src;
-    [Reflect] attribute DOMString type;
-    [Reflect] attribute DOMString crossOrigin;
-    [Reflect, EnabledAtRuntime=ExperimentalContentSecurityPolicyFeatures] attribute DOMString nonce;
+    [Reflect, TreatNullAs=NullString, URL] attribute DOMString src;
+    [Reflect, TreatNullAs=NullString] attribute DOMString type;
+    [Reflect, TreatNullAs=NullString] attribute DOMString crossOrigin;
+    [Reflect, TreatNullAs=NullString, EnabledAtRuntime=ExperimentalContentSecurityPolicyFeatures] attribute DOMString nonce;
 };