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

ios/chrome/browser/ui/settings/accounts_collection_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 <EarlGrey/EarlGrey.h>
 #import <XCTest/XCTest.h>
 
 #include "base/strings/sys_string_conversions.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #import "ios/chrome/browser/ui/settings/accounts_collection_view_controller.h"
 #import "ios/chrome/browser/ui/settings/settings_collection_view_controller.h"
 #include "ios/chrome/browser/ui/tools_menu/tools_menu_constants.h"
 #import "ios/chrome/browser/ui/tools_menu/tools_popup_controller.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/chrome/test/app/chrome_test_util.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"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Returns a fake identity.
 ChromeIdentity* GetFakeIdentity1() {
   return [FakeChromeIdentity identityWithEmail:@"foo@gmail.com"
                                         gaiaID:@"fooID"
                                           name:@"Fake Foo"];
 }
 
 // Returns a second fake identity.
@@ skipping 270 matching lines @@
   // Check that Account Settings screen is open and |identity| is signed in.
   [[EarlGrey selectElementWithMatcher:grey_accessibilityID(kSettingsAccountsId)]
       assertWithMatcher:grey_sufficientlyVisible()];
   AssertAuthenticatedIdentityInActiveProfile(identity);
 
   // Close Settings.
   TapButtonWithLabelId(IDS_IOS_NAVIGATION_BAR_DONE_BUTTON);
 }
 
 @end