[Mac] Take Sierra RTL into account when laying out window buttons

chrome/browser/ui/cocoa/framed_browser_window.mm

 // Copyright (c) 2012 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 "chrome/browser/ui/cocoa/framed_browser_window.h"
 
 #include <math.h>
 #include <objc/runtime.h>
 #include <stddef.h>
 
@@ skipping 117 matching lines @@
     [self setAutorecalculatesContentBorderThickness:NO forEdge:NSMaxYEdge];
     [self setContentBorderThickness:kWindowGradientHeight forEdge:NSMaxYEdge];
 
     hasTabStrip_ = hasTabStrip;
     closeButton_ = [self standardWindowButton:NSWindowCloseButton];
     miniaturizeButton_ = [self standardWindowButton:NSWindowMiniaturizeButton];
     zoomButton_ = [self standardWindowButton:NSWindowZoomButton];
 
     windowButtonsInterButtonSpacing_ =
         NSMinX([miniaturizeButton_ frame]) - NSMaxX([closeButton_ frame]);
+    if (windowButtonsInterButtonSpacing_ < 0)
+      // Sierra RTL
+      windowButtonsInterButtonSpacing_ =
+          NSMinX([miniaturizeButton_ frame]) - NSMaxX([zoomButton_ frame]);
 
     NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
     if (shouldUseFullSizeContentView) {
       // If Chrome uses full sized content view then window buttons are placed
       // inside titlebar (which height is 22 points). In order to move window
       // buttons down the whole toolbar should be moved down.
       DCHECK(closeButton_);
       NSView* titlebarContainer = [[closeButton_ superview] superview];
       [self adjustTitlebarContainer:titlebarContainer];
       [center addObserver:self
@@ skipping 373 matching lines @@
   [self childWindowsDidChange];
 }
 
 - (void)childWindowsDidChange {
   id delegate = [self delegate];
   if ([delegate respondsToSelector:@selector(childWindowsDidChange)])
     [delegate childWindowsDidChange];
 }
 
 @end