Use new Traversal<HTML*Element> API in HTML code

Source/core/html/HTMLAppletElement.cpp

Index: Source/core/html/HTMLAppletElement.cpp
diff --git a/Source/core/html/HTMLAppletElement.cpp b/Source/core/html/HTMLAppletElement.cpp
index 7dafb109370b2f9e3cd5f4dfec460665f0b4259a..7620bea6111d841515870b5b0634509045913b84 100644
--- a/Source/core/html/HTMLAppletElement.cpp
+++ b/Source/core/html/HTMLAppletElement.cpp
@@ -167,11 +167,7 @@ void HTMLAppletElement::updateWidgetInternal()
         paramValues.append(mayScript.string());
     }
 
-    for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
-        if (!child->hasTagName(paramTag))
-            continue;
-
-        HTMLParamElement* param = toHTMLParamElement(child);
+    for (HTMLParamElement* param = Traversal<HTMLParamElement>::firstChild(*this); param; param = Traversal<HTMLParamElement>::nextSibling(*param)) {
         if (param->name().isEmpty())
             continue;