Add ScopedMacRTL class for Cocoa browser RTL testing

chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm

Index: chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm
diff --git a/chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm b/chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm
index 13e7fab50156145572600031057f433514afeca8..071044d79f21719aad102aed8d5340d8c1cdde89 100644
--- a/chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm
+++ b/chrome/browser/ui/cocoa/profiles/avatar_button_controller.mm
@@ -16,7 +16,7 @@
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
-#include "chrome/browser/ui/cocoa/l10n_util.h"
+#import "ui/base/cocoa/rtl_util.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_button.h"
 #include "chrome/grit/generated_resources.h"
 #import "chrome/browser/themes/theme_properties.h"
@@ -179,7 +179,7 @@ const CGFloat kTitleKern = 0.25;
       [[avatarButton cell] setHighlightsBy:NSNoCellMask];
     [avatarButton setBordered:YES];
 
-    if (cocoa_l10n_util::ShouldDoExperimentalRTLLayout())
+    if (cocoa_rtl_util::ShouldDoExperimentalRTLLayout())
       [avatarButton setAutoresizingMask:NSViewMaxXMargin | NSViewMinYMargin];
     else
       [avatarButton setAutoresizingMask:NSViewMinXMargin | NSViewMinYMargin];