Use new Traversal<> API more in the code base

Source/core/css/AffectedByFocusTest.cpp

 // 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 "config.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/StyleEngine.h"
@@ skipping 41 matching lines @@
 
 void AffectedByFocusTest::setHtmlInnerHTML(const char* htmlContent)
 {
     document().documentElement()->setInnerHTML(String::fromUTF8(htmlContent), ASSERT_NO_EXCEPTION);
     document().view()->updateLayoutAndStyleIfNeededRecursive();
 }
 
 void AffectedByFocusTest::checkElements(ElementResult expected[], unsigned expectedCount) const
 {
     unsigned i = 0;
-    Element* elm = document().body();
+    HTMLElement* element = document().body();
 
-    for (; elm && i < expectedCount; elm = ElementTraversal::next(*elm), ++i) {
-        ASSERT_TRUE(elm->hasTagName(expected[i].tag));
-        ASSERT(elm->renderStyle());
-        ASSERT_EQ(expected[i].affectedBy, elm->renderStyle()->affectedByFocus());
-        ASSERT_EQ(expected[i].childrenOrSiblingsAffectedBy, elm->childrenOrSiblingsAffectedByFocus());
+    for (; element && i < expectedCount; element = Traversal<HTMLElement>::next(*element), ++i) {
+        ASSERT_TRUE(element->hasTagName(expected[i].tag));
+        ASSERT(element->renderStyle());
+        ASSERT_EQ(expected[i].affectedBy, element->renderStyle()->affectedByFocus());
+        ASSERT_EQ(expected[i].childrenOrSiblingsAffectedBy, element->childrenOrSiblingsAffectedByFocus());
     }
 
-    ASSERT(!elm && i == expectedCount);
+    ASSERT(!element && i == expectedCount);
 }
 
 // A global :focus rule in html.css currently causes every single element to be
 // affectedByFocus. Check that all elements in a document with no :focus rules
 // gets the affectedByFocus set on RenderStyle and not childrenOrSiblingsAffectedByFocus.
 TEST_F(AffectedByFocusTest, UAUniversalFocusRule)
 {
     ElementResult expected[] = {
         { bodyTag, true, false },
         { divTag, true, false },
@@ skipping 226 matching lines @@
 
     document().getElementById("d")->focus();
     document().view()->updateLayoutAndStyleIfNeededRecursive();
 
     unsigned accessCount = document().styleEngine()->resolverAccessCount() - startCount;
 
     ASSERT_EQ(1U, accessCount);
 }
 
 } // namespace