Add ScopedMacRTL class for Cocoa browser RTL testing

ui/base/test/scoped_mac_rtl.mm

+// Copyright 2016 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 "ui/base/test/scoped_mac_rtl.h"
+
+#include "base/i18n/rtl.h"
+#include "ui/base/cocoa/rtl_util.h"
+
+namespace {
+NSString* const kAppleTextDirectionDefaultsKey = @"AppleTextDirection";
+NSString* const kForceRTLWritingDirectionDefaultsKey =
+    @"NSForceRightToLeftWritingDirection";
+}  // namespace

[Robert Sesek, 2016/12/07 16:09:59]

nit: blank line after

+namespace cocoa_rtl_util {

[Robert Sesek, 2016/12/07 16:09:59]

nit: blank lines around inside of the namespace

+ScopedMacRTL::ScopedMacRTL() {
+  scoped_feature_list_.InitAndEnableFeature(
+      cocoa_rtl_util::kExperimentalMacRTL);
+  NSUserDefaults* standard_defaults = [NSUserDefaults standardUserDefaults];
+  original_apple_text_direction_ =
+      [standard_defaults boolForKey:kAppleTextDirectionDefaultsKey];
+  original_rtl_writing_direction_ =
+      [standard_defaults boolForKey:kForceRTLWritingDirectionDefaultsKey];
+  [standard_defaults setBool:YES forKey:kAppleTextDirectionDefaultsKey];
+  [standard_defaults setBool:YES forKey:kForceRTLWritingDirectionDefaultsKey];
+  original_locale_ = base::i18n::GetConfiguredLocale();
+  base::i18n::SetICUDefaultLocale("he");
+}

[Robert Sesek, 2016/12/07 16:09:59]

nit: blank line after

+ScopedMacRTL::~ScopedMacRTL() {
+  [[NSUserDefaults standardUserDefaults]
+      setBool:original_apple_text_direction_
+       forKey:kAppleTextDirectionDefaultsKey];
+  [[NSUserDefaults standardUserDefaults]
+      setBool:original_rtl_writing_direction_
+       forKey:kForceRTLWritingDirectionDefaultsKey];
+  base::i18n::SetICUDefaultLocale(original_locale_);
+}
+
+}  // namespace cocoa_rtl_util