Remove some useless null checks in Element/NamedNodeMap

Source/core/dom/Element.h

Index: Source/core/dom/Element.h
diff --git a/Source/core/dom/Element.h b/Source/core/dom/Element.h
index 5b42acc28c18bf285bc4d79e2df2ef2f766e88cd..ffe6f3b9c206afd166ef62e569c2fe9ab97cde3a 100644
--- a/Source/core/dom/Element.h
+++ b/Source/core/dom/Element.h
@@ -287,6 +287,8 @@ public:
     const AtomicString& getNameAttribute() const;
     const AtomicString& getClassAttribute() const;
 
+    bool shouldIgnoreAttributeCase() const;
+
     // Call this to get the value of the id attribute for style resolution purposes.
     // The value will already be lowercased if the document is in compatibility mode,
     // so this function is not suitable for non-style uses.
@@ -882,6 +884,11 @@ inline const AtomicString& Element::getClassAttribute() const
     return fastGetAttribute(HTMLNames::classAttr);
 }
 
+inline bool Element::shouldIgnoreAttributeCase() const
+{
+    return isHTMLElement() && document().isHTMLDocument();
+}
+
 inline void Element::setIdAttribute(const AtomicString& value)
 {
     setAttribute(document().idAttributeName(), value);