printing: Replace "using namespace printing;" wrapping the tests around "namespace printing { ... }"

printing/units_unittest.cc

 // Copyright (c) 2011 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 "printing/units.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest/include/gtest/gtest-spi.h"
 
-using namespace printing;
+namespace printing {
 
 TEST(UnitsTest, Convertions) {
   EXPECT_EQ(100, ConvertUnit(100, 100, 100));
   EXPECT_EQ(-100, ConvertUnit(-100, 100, 100));
   EXPECT_EQ(0, ConvertUnit(0, 100, 100));
   EXPECT_EQ(99, ConvertUnit(99, 100, 100));
   EXPECT_EQ(101, ConvertUnit(101, 100, 100));
   EXPECT_EQ(99900, ConvertUnit(999, 10, 1000));
   EXPECT_EQ(100100, ConvertUnit(1001, 10, 1000));
 
@@ skipping 32 matching lines @@
   EXPECT_EQ(0, ConvertHundredThousanthMeterToMilliInch(0));
 
   EXPECT_EQ(8.25, ConvertPixelsToPointDouble(11.0));
   // Round down.
   EXPECT_EQ(8, ConvertPixelsToPoint(11));
   EXPECT_EQ(7.5, ConvertPixelsToPointDouble(10.0));
   // Round up.
   EXPECT_EQ(8, ConvertPixelsToPoint(10));
   EXPECT_EQ(0, ConvertPixelsToPoint(0));
 }
+
+}  // namespace printing