Revert of base: Remove using:: declaration from version.h header.

base/version_unittest.cc

 // Copyright (c) 2012 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 "base/version.h"
 
-#include "base/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace base {
 namespace {
 
 TEST(VersionTest, DefaultConstructor) {
   Version v;
   EXPECT_FALSE(v.IsValid());
 }
 
 TEST(VersionTest, ValueSemantics) {
   Version v1("1.2.3.4");
   EXPECT_TRUE(v1.IsValid());
@@ skipping 126 matching lines @@
     {"*", false},
     {"*.2", false},
   };
   for (size_t i = 0; i < arraysize(cases); ++i) {
     EXPECT_EQ(Version::IsValidWildcardString(cases[i].version),
         cases[i].expected) << cases[i].version << "?" << cases[i].expected;
   }
 }
 
 }  // namespace
-}  // namespace base