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

Source/core/dom/DOMImplementationTest.cpp

 /*
  * Copyright (c) 2013, Opera Software ASA. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 15 matching lines @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/dom/DOMImplementation.h"
 
 #include "wtf/text/WTFString.h"
 #include <gtest/gtest.h>
 
-using namespace blink;
-
-namespace {
+namespace blink {
 
 TEST(DOMImplementationTest, TextMIMEType)
 {
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("text/plain"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("text/javascript"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("TEXT/JavaScript"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("application/json"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("application/jSON"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("application/json;foo=2"));
     EXPECT_TRUE(DOMImplementation::isTextMIMEType("application/json  "));
@@ skipping 39 matching lines @@
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/x-custom+exml"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("text/html"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/xml;"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/xml "));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/x-what+xml;"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/x-tra+xML;a=2"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/+xML"));
     EXPECT_FALSE(DOMImplementation::isXMLMIMEType("application/+xml"));
 }
 
-}
+} // namespace blink