Fixes crash in unittests. This happened as the result of making the

ui/base/native_theme/native_theme_win.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 "ui/base/native_theme/native_theme_win.h"
 
 #include <windows.h>
 #include <uxtheme.h>
 #include <vsstyle.h>
 #include <vssym32.h>
@@ skipping 174 matching lines @@
   }
 }
 
 bool NativeThemeWin::IsClassicTheme(ThemeName name) const {
   if (!theme_dll_)
     return true;
 
   return !GetThemeHandle(name);
 }
 
+// TODO(sky): seems like we should default to NativeThemeWin, but that currently
+// breaks a couple of tests (FocusTraversalTest.NormalTraversal in
+// views_unittests).
+#if !defined(USE_AURA)
 // static
 NativeTheme* NativeTheme::instance() {
   return NativeThemeWin::instance();
 }
+#endif
 
 // static
 NativeThemeWin* NativeThemeWin::instance() {
   CR_DEFINE_STATIC_LOCAL(NativeThemeWin, s_native_theme, ());
   return &s_native_theme;
 }
 
 NativeThemeWin::NativeThemeWin()
     : theme_dll_(LoadLibrary(L"uxtheme.dll")),
       draw_theme_(NULL),
@@ skipping 1601 matching lines @@
     handle = open_theme_(NULL, L"Spin");
     break;
   default:
     NOTREACHED();
   }
   theme_handles_[theme_name] = handle;
   return handle;
 }
 
 }  // namespace ui