Remove TreatNullAs=NullString for <frame>, <frameset> and <iframe>

Source/core/html/HTMLIFrameElement.idl

Index: Source/core/html/HTMLIFrameElement.idl
diff --git a/Source/core/html/HTMLIFrameElement.idl b/Source/core/html/HTMLIFrameElement.idl
index 42f3b4f6b96656413380306960f633e4f00f0a3f..d8a8a8eb70076db77f0fe5720450b414efc60842 100644
--- a/Source/core/html/HTMLIFrameElement.idl
+++ b/Source/core/html/HTMLIFrameElement.idl
@@ -19,19 +19,19 @@
  */
 
 interface HTMLIFrameElement : HTMLElement {
-    [Reflect, TreatNullAs=NullString] attribute DOMString align;
-    [Reflect, TreatNullAs=NullString] attribute DOMString frameBorder;
-    [Reflect, TreatNullAs=NullString] attribute DOMString height;
-    [Reflect, TreatNullAs=NullString] attribute DOMString longDesc;
+    [Reflect] attribute DOMString align;
+    [Reflect] attribute DOMString frameBorder;
+    [Reflect] attribute DOMString height;
+    [Reflect, URL] attribute DOMString longDesc;
     [Reflect, TreatNullAs=NullString] attribute DOMString marginHeight;
     [Reflect, TreatNullAs=NullString] attribute DOMString marginWidth;
-    [Reflect, TreatNullAs=NullString] attribute DOMString name;
+    [Reflect] attribute DOMString name;
     [Reflect, TreatNullAs=NullString] attribute DOMString sandbox;
     [Reflect, RuntimeEnabled=SeamlessIFrames] attribute boolean seamless;
-    [Reflect, TreatNullAs=NullString] attribute DOMString scrolling;
-    [Reflect, TreatNullAs=NullString, URL, PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds] attribute DOMString src;
-    [Reflect, TreatNullAs=NullString] attribute DOMString srcdoc;
-    [Reflect, TreatNullAs=NullString] attribute DOMString width;
+    [Reflect] attribute DOMString scrolling;
+    [Reflect, URL, PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds] attribute DOMString src;
+    [Reflect] attribute DOMString srcdoc;
+    [Reflect] attribute DOMString width;
 
     // Introduced in DOM Level 2:
     [CheckSecurity=Node] readonly attribute Document contentDocument;
@@ -41,4 +41,3 @@ interface HTMLIFrameElement : HTMLElement {
 
     [CheckSecurity=Node, RaisesException] SVGDocument getSVGDocument();
 };
-