[Mac] Mirror profile switcher UI in RTL

chrome/browser/ui/cocoa/l10n_util.mm

Index: chrome/browser/ui/cocoa/l10n_util.mm
diff --git a/chrome/browser/ui/cocoa/l10n_util.mm b/chrome/browser/ui/cocoa/l10n_util.mm
index 03d772ee7b1109ad6e0ea4b4d1ab5d70f05c6987..768fe5a83861ba898dd715c4904cbbd03ee5b138 100644
--- a/chrome/browser/ui/cocoa/l10n_util.mm
+++ b/chrome/browser/ui/cocoa/l10n_util.mm
@@ -117,6 +117,14 @@ NSCellImagePosition TrailingCellImagePosition() {
 }
 #endif  // MAC_OS_X_VERSION_10_12
 
+NSRectEdge LeadingEdge() {
+  return ShouldDoExperimentalRTLLayout() ? NSMaxXEdge : NSMinXEdge;
+}
+
+NSRectEdge TrailingEdge() {
+  return ShouldDoExperimentalRTLLayout() ? NSMinXEdge : NSMaxXEdge;
+}
+
 // Adapted from Apple's RTL docs (goo.gl/cBaFnT)
 NSImage* FlippedImage(NSImage* image) {
   const NSSize size = [image size];