Only refer to _WIN resources on Windows.

chrome/browser/managed_mode/managed_user_theme.cc

 // Copyright 2013 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 "chrome/browser/managed_mode/managed_user_theme.h"
 
 #include "chrome/browser/themes/theme_properties.h"
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 
 namespace {
 
 const SkColor kDefaultColorFrameManagedUser = SkColorSetRGB(165, 197, 225);
 const SkColor kDefaultColorFrameManagedUserInactive =
     SkColorSetRGB(180, 225, 247);
 const SkColor kDefaultColorManagedUserLabelBackground =
     SkColorSetRGB(108, 167, 210);
 
 // Map resource ids to the managed user resource ids.
 int MapToManagedUserResourceIds(int id) {
   switch (id) {
     case IDR_THEME_FRAME:
+#if defined(OS_WIN)
     case IDR_THEME_FRAME_WIN:
+#endif
       return IDR_MANAGED_USER_THEME_FRAME;
     case IDR_THEME_FRAME_INACTIVE:
+#if defined(OS_WIN)
     case IDR_THEME_FRAME_INACTIVE_WIN:
+#endif
       return IDR_MANAGED_USER_THEME_FRAME_INACTIVE;
     case IDR_THEME_TAB_BACKGROUND:
     case IDR_THEME_TAB_BACKGROUND_V:
+#if defined(OS_WIN)
     case IDR_THEME_TAB_BACKGROUND_WIN:
+#endif
       return IDR_MANAGED_USER_THEME_TAB_BACKGROUND;
   }
   return id;
 }
 
 }  // namespace
 
 ManagedUserTheme::ManagedUserTheme()
     : CustomThemeSupplier(MANAGED_USER_THEME) {}
 
@@ skipping 21 matching lines @@
   if (!HasCustomImage(id))
     return gfx::Image();
 
   id = MapToManagedUserResourceIds(id);
   return ResourceBundle::GetSharedInstance().GetNativeImageNamed(id);
 }
 
 bool ManagedUserTheme::HasCustomImage(int id) const {
   return id != MapToManagedUserResourceIds(id);
 }