[Mac] Reverse tabs in RTL mode

chrome/browser/ui/cocoa/l10n_util.h

 // Copyright (c) 2010 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.
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
+#include "base/feature_list.h"
 #include "base/strings/string16.h"
 
 namespace cocoa_l10n_util {
 
 // Compare function for -[NSArray sortedArrayUsingFunction:context:] that
 // sorts the views in Y order bottom up. |context| is ignored.
 NSInteger CompareFrameY(id view1, id view2, void* context);
 
 // Helper for tweaking views. If view is a:
 //   checkbox, radio group or label: it gets a forced wrap at current size
 //   editable field: left as is
 //   anything else: do  +[GTMUILocalizerAndLayoutTweaker sizeToFitView:]
 NSSize WrapOrSizeToFit(NSView* view);
 
 // Walks views in top-down order, wraps each to their current width, and moves
 // the latter ones down to prevent overlaps. Returns the vertical delta in view
 // coordinates.
 CGFloat VerticallyReflowGroup(NSArray* views);
 
 // Like |base::ReplaceStringPlaceholders(const base::string16&,
 // const base::string16&, size_t*)|, but for a NSString formatString.
 NSString* ReplaceNSStringPlaceholders(NSString* formatString,
                                       const base::string16& a,
                                       size_t* offset);
 
 // 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();
 
 }  // namespace cocoa_l10n_util