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

Source/core/editing/SurroundingTextTest.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/editing/SurroundingText.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Position.h"
 #include "core/dom/Range.h"
 #include "core/dom/Text.h"
 #include "core/editing/VisibleSelection.h"
 #include "core/html/HTMLElement.h"
 #include "core/testing/DummyPageHolder.h"
 #include <gtest/gtest.h>
 
-using namespace blink;
-
-namespace {
+namespace blink {
 
 class SurroundingTextTest : public ::testing::Test {
 protected:
     Document& document() const { return m_dummyPageHolder->document(); }
     void setHTML(const String&);
     VisibleSelection select(int offset) { return select(offset, offset); }
     VisibleSelection select(int start, int end);
 
 private:
-    virtual void SetUp() override;
+    void SetUp() override;
 
     OwnPtr<DummyPageHolder> m_dummyPageHolder;
 };
 
 void SurroundingTextTest::SetUp()
 {
     m_dummyPageHolder = DummyPageHolder::create(IntSize(800, 600));
 }
 
 void SurroundingTextTest::setHTML(const String& content)
@@ skipping 215 matching lines @@
     {
         VisibleSelection selection = select(0, 7);
         SurroundingText surroundingText(*selection.firstRange(), 1337);
 
         EXPECT_EQ("This is outside of foo bar the selected node", surroundingText.content().simplifyWhiteSpace());
         EXPECT_EQ(20u, surroundingText.startOffsetInContent());
         EXPECT_EQ(27u, surroundingText.endOffsetInContent());
     }
 }
 
-} // anonymous namespace
+} // namespace blink