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

ui/base/native_theme/native_theme_win_unittest.cc

Index: ui/base/native_theme/native_theme_win_unittest.cc
diff --git a/ui/gfx/native_theme_win_unittest.cc b/ui/base/native_theme/native_theme_win_unittest.cc
similarity index 64%
rename from ui/gfx/native_theme_win_unittest.cc
rename to ui/base/native_theme/native_theme_win_unittest.cc
index cce38614c742a9b57780e7a2c88620758ac5918f..dadfd7284da0275a784a6bef01a1ce5307e1e392 100644
--- a/ui/gfx/native_theme_win_unittest.cc
+++ b/ui/base/native_theme/native_theme_win_unittest.cc
@@ -2,10 +2,14 @@
 // 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 "ui/base/native_theme/native_theme_win.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace ui {
+
 TEST(NativeThemeTest, Init) {
-  ASSERT_TRUE(gfx::NativeThemeWin::instance() != NULL);
+  ASSERT_TRUE(NativeThemeWin::instance() != NULL);
 }
+
+}  // namespace ui