ui: Move NativeTheme files into ui/base/native_theme/ directory.

ui/gfx/native_theme_win_unittest.cc

Index: ui/gfx/native_theme_win_unittest.cc
diff --git a/ui/gfx/native_theme_win_unittest.cc b/ui/gfx/native_theme_win_unittest.cc
deleted file mode 100644
index cce38614c742a9b57780e7a2c88620758ac5918f..0000000000000000000000000000000000000000
--- a/ui/gfx/native_theme_win_unittest.cc
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2009 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 "ui/gfx/native_theme_win.h"
-
-#include "testing/gtest/include/gtest/gtest.h"
-
-TEST(NativeThemeTest, Init) {
-  ASSERT_TRUE(gfx::NativeThemeWin::instance() != NULL);
-}