Fixed perf regression by removing tree traversal for text sibling.

third_party/WebKit/Source/core/dom/Node.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, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  *
@@ skipping 372 matching lines @@
   while (node->parentNode())
     node = node->parentNode();
   return const_cast<Node&>(*node);
 }
 
 Node* Node::getRootNode(const GetRootNodeOptions& options) const {
   return (options.hasComposed() && options.composed()) ? &shadowIncludingRoot()
                                                        : &treeRoot();
 }
 
-Text* Node::nextTextSibling() const {
-  for (Node* sibling = nextSibling();
-       sibling &&
-       (!sibling->isElementNode() || !toElement(sibling)->layoutObject());
-       sibling = sibling->nextSibling()) {
-    if (sibling->isTextNode()) {
-      return toText(sibling);
-    }
-  }
-  return nullptr;
-}
-
 Node* Node::insertBefore(Node* newChild,
                          Node* refChild,
                          ExceptionState& exceptionState) {
   if (isContainerNode())
     return toContainerNode(this)->insertBefore(newChild, refChild,
                                                exceptionState);
 
   exceptionState.throwDOMException(
       HierarchyRequestError, "This node type does not support this method.");
   return nullptr;
@@ skipping 2074 matching lines @@
   if (node) {
     std::stringstream stream;
     node->printNodePathTo(stream);
     LOG(INFO) << stream.str();
   } else {
     LOG(INFO) << "Cannot showNodePath for <null>";
   }
 }
 
 #endif