Add ScopedMacRTL class for Cocoa browser RTL testing

chrome/browser/ui/cocoa/l10n_util.h

Index: chrome/browser/ui/cocoa/l10n_util.h
diff --git a/chrome/browser/ui/cocoa/l10n_util.h b/chrome/browser/ui/cocoa/l10n_util.h
index a7d8a8069652f35ec6f90a85f348fb7419e0b50c..64a70e7a2638bdcd4131bb88bb1a0437d77a27be 100644
--- a/chrome/browser/ui/cocoa/l10n_util.h
+++ b/chrome/browser/ui/cocoa/l10n_util.h
@@ -5,7 +5,6 @@
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
-#include "base/feature_list.h"
 #include "base/strings/string16.h"
 
 namespace cocoa_l10n_util {
@@ -34,19 +33,4 @@ NSString* ReplaceNSStringPlaceholders(NSString* formatString,
 // Generates a tooltip string for a given URL and title.
 NSString* TooltipForURLAndTitle(NSString* url, NSString* title);
 
-extern const base::Feature kExperimentalMacRTL;
-// Returns whether both:
-// 1) Experimental Mac RTL support is enabled via the ExperimentalMacRTL
-//    feature;
-// 2) The browser UI is in RTL mode.
-// If ExperimentalMacRTL becomes the default, this function can be replaced with
-// uses of base::i18n::IsRTL().
-bool ShouldDoExperimentalRTLLayout();
-
-// Returns true if ShouldDoExperimentalRTLLayout() is true and the OS is
-// 10.12 or above. macOS 10.12 is the first OS where the native stoplight
-// buttons are reversed in RTL, so manually reversing them in previous
-// OSes would make Chrome stick out.
-bool ShouldFlipWindowControlsInRTL();
-
 }  // namespace cocoa_l10n_util