[ObjC ARC] Converts ios/chrome/browser/ui/settings:eg_tests to ARC.

ios/chrome/browser/ui/settings/clear_browsing_data_egtest.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.
 
 #import <XCTest/XCTest.h>
 
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/ui/tools_menu/tools_menu_constants.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/chrome/test/earl_grey/chrome_earl_grey.h"
 #import "ios/chrome/test/earl_grey/chrome_earl_grey_ui.h"
 #import "ios/chrome/test/earl_grey/chrome_matchers.h"
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
 #include "ui/base/l10n/l10n_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 using chrome_test_util::ButtonWithAccessibilityLabel;
 using chrome_test_util::ButtonWithAccessibilityLabelId;
 using chrome_test_util::NavigationBarDoneButton;
 
 @interface ClearBrowsingDataSettingsTestCase : ChromeTestCase
 @end
 
 @implementation ClearBrowsingDataSettingsTestCase
 
 - (void)openClearBrowsingDataDialog {
@@ skipping 28 matching lines @@
       [defaults stringForKey:@"EnableNewClearBrowsingDataUI"];
   [defaults setObject:@"Enabled" forKey:@"EnableNewClearBrowsingDataUI"];
 
   [self openClearBrowsingDataDialog];
   [self exitSettingsMenu];
 
   [defaults setObject:oldSetting forKey:@"EnableNewClearBrowsingDataUI"];
 }
 
 @end