Fix unit test style in core/{dom,editing,html}/.

Source/core/html/HTMLFormControlElementTest.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/html/HTMLFormControlElement.h"
 
 #include "core/frame/FrameView.h"
 #include "core/html/HTMLDocument.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/layout/LayoutObject.h"
 #include "core/loader/EmptyClients.h"
 #include "core/testing/DummyPageHolder.h"
 #include <gtest/gtest.h>
 
 namespace blink {
 
 class HTMLFormControlElementTest : public ::testing::Test {
 protected:
-    virtual void SetUp() override;
+    void SetUp() override;
 
     DummyPageHolder& page() const { return *m_dummyPageHolder; }
     HTMLDocument& document() const { return *m_document; }
 
 private:
     OwnPtr<DummyPageHolder> m_dummyPageHolder;
     RefPtrWillBePersistent<HTMLDocument> m_document;
 };
 
 void HTMLFormControlElementTest::SetUp()
@@ skipping 29 matching lines @@
     EXPECT_EQ(RTL, messageDir);
     EXPECT_EQ(RTL, subMessageDir);
 
     input->setCustomValidity(String::fromUTF8("Main message."));
     message = input->validationMessage().stripWhiteSpace();
     input->findCustomValidationMessageTextDirection(message, messageDir, subMessage, subMessageDir);
     EXPECT_EQ(LTR, messageDir);
     EXPECT_EQ(RTL, subMessageDir);
 }
 
-}
+} // namespace blink