Revert of [ObjC ARC] Converts ios/chrome/browser/ui:ui to ARC.

ios/chrome/browser/ui/rtl_geometry.mm

 // Copyright 2015 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.
 
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 
 #import <UIKit/UIKit.h>
 #include <limits>
 
 #include "base/logging.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
 bool UseRTLLayout() {
   return base::i18n::IsRTL();
 }
 
 base::i18n::TextDirection LayoutDirection() {
   return UseRTLLayout() ? base::i18n::RIGHT_TO_LEFT : base::i18n::LEFT_TO_RIGHT;
 }
 
 #pragma mark - LayoutRects.
 
@@ skipping 247 matching lines @@
 }
 
 #pragma mark - autolayout utilities
 
 NSLayoutFormatOptions LayoutOptionForRTLSupport() {
   if (UseRTLLayout()) {
     return NSLayoutFormatDirectionLeadingToTrailing;
   }
   return NSLayoutFormatDirectionLeftToRight;
 }