Remove dom_utils.

content/renderer/dom_utils.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "content/renderer/dom_utils.h"
-
-#include "third_party/WebKit/public/web/WebNode.h"
-
-namespace content {
-
-blink::WebNode DomUtils::ExtractParentAnchorNode(
-    const blink::WebNode& node) {
-  blink::WebNode selected_node = node;
-
-  // If there are other embedded tags (like <a ..>Some <b>text</b></a>)
-  // we need to extract the parent <a/> node.
-  while (!selected_node.isNull() && !selected_node.isLink())
-    selected_node = selected_node.parentNode();
-  return selected_node;
-}
-
-}  // namespace content