Use Traversal<>::firstAncestor() API more in the code base

Source/core/html/HTMLMetaElement-in.cpp

Index: Source/core/html/HTMLMetaElement-in.cpp
diff --git a/Source/core/html/HTMLMetaElement-in.cpp b/Source/core/html/HTMLMetaElement-in.cpp
index 1a88b7135160c7fc9cc090ff8c8e2ea51851759f..c9c8509afbfd485d7f8ca9e33648f3740535c6ce 100644
--- a/Source/core/html/HTMLMetaElement-in.cpp
+++ b/Source/core/html/HTMLMetaElement-in.cpp
@@ -25,8 +25,10 @@
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
+#include "core/html/HTMLHeadElement.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "platform/RuntimeEnabledFeatures.h"
@@ -448,11 +450,7 @@ static bool inDocumentHead(HTMLMetaElement* element)
     if (!element->inDocument())
         return false;
 
-    for (Element* current = element; current; current = current->parentElement()) {
-        if (isHTMLHeadElement(*current))
-            return true;
-    }
-    return false;
+    return Traversal<HTMLHeadElement>::firstAncestor(*element);
 }
 
 void HTMLMetaElement::process()