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

ios/chrome/browser/ui/history/history_ui_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 <UIKit/UIKit.h>
 #import <XCTest/XCTest.h>
 
 #include "base/strings/sys_string_conversions.h"
 #include "components/browsing_data/core/pref_names.h"
@@ skipping 18 matching lines @@
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
 #import "ios/public/provider/chrome/browser/signin/chrome_identity.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
 #import "ios/testing/wait_util.h"
 #import "ios/web/public/test/http_server.h"
 #import "ios/web/public/test/http_server_util.h"
 #import "net/base/mac/url_conversions.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::ButtonWithAccessibilityLabelId;
 
 namespace {
 char kURL1[] = "http://firstURL";
 char kURL2[] = "http://secondURL";
 char kURL3[] = "http://thirdURL";
 char kResponse1[] = "Test Page 1";
 char kResponse2[] = "Test Page 2";
 char kResponse3[] = "Test Page 3";
 
@@ skipping 448 matching lines @@
 - (void)resetBrowsingDataPrefs {
   PrefService* prefs = chrome_test_util::GetOriginalBrowserState()->GetPrefs();
   prefs->ClearPref(browsing_data::prefs::kDeleteBrowsingHistory);
   prefs->ClearPref(browsing_data::prefs::kDeleteCookies);
   prefs->ClearPref(browsing_data::prefs::kDeleteCache);
   prefs->ClearPref(browsing_data::prefs::kDeletePasswords);
   prefs->ClearPref(browsing_data::prefs::kDeleteFormData);
 }
 
 @end