Add ScopedMacRTL class for Cocoa browser RTL testing

chrome/browser/ui/cocoa/browser_window_controller.mm

Index: chrome/browser/ui/cocoa/browser_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index cffc7903dba949c70785bf87e4f1da21218f1e2f..c84562ff5d46d25d5b9f97d3eb3468092f04f61c 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -61,7 +61,7 @@
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_visibility_lock_controller.h"
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_controller.h"
-#include "chrome/browser/ui/cocoa/l10n_util.h"
+#import "ui/base/cocoa/rtl_util.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_base_controller.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_button_controller.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_icon_controller.h"
@@ -1635,7 +1635,7 @@ bool IsTabDetachingInFullscreenEnabled() {
       [[AvatarIconController alloc] initWithBrowser:browser_.get()]);
   }
   view = [avatarButtonController_ view];
-  if (cocoa_l10n_util::ShouldDoExperimentalRTLLayout())
+  if (cocoa_rtl_util::ShouldDoExperimentalRTLLayout())
     [view setAutoresizingMask:NSViewMaxXMargin | NSViewMinYMargin];
   else
     [view setAutoresizingMask:NSViewMinXMargin | NSViewMinYMargin];