Remove always-false null checks for getElementsByTagName(NS)

third_party/WebKit/Source/core/dom/ContainerNode.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 1447 matching lines @@
     document().invalidateNodeListCaches(attrName);
 
     for (ContainerNode* node = this; node; node = node->parentNode()) {
         if (NodeListsNodeData* lists = node->nodeLists())
             lists->invalidateCaches(attrName);
     }
 }
 
 PassRefPtrWillBeRawPtr<TagCollection> ContainerNode::getElementsByTagName(const AtomicString& localName)
 {
-    if (localName.isNull())
-        return nullptr;
-
     if (document().isHTMLDocument())
         return ensureCachedCollection<HTMLTagCollection>(HTMLTagCollectionType, localName);
     return ensureCachedCollection<TagCollection>(TagCollectionType, localName);
 }
 
 PassRefPtrWillBeRawPtr<TagCollection> ContainerNode::getElementsByTagNameNS(const AtomicString& namespaceURI, const AtomicString& localName)
 {
-    if (localName.isNull())
-        return nullptr;
-
     if (namespaceURI == starAtom)
         return getElementsByTagName(localName);
 
     return ensureCachedCollection<TagCollection>(TagCollectionType, namespaceURI.isEmpty() ? nullAtom : namespaceURI, localName);
 }
 
 // Takes an AtomicString in argument because it is common for elements to share the same name attribute.
 // Therefore, the NameNodeList factory function expects an AtomicString type.
 PassRefPtrWillBeRawPtr<NameNodeList> ContainerNode::getElementsByName(const AtomicString& elementName)
 {
@@ skipping 52 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace blink