[ObjC ARC] Converts ios/chrome/test/app:test_support to ARC.

ios/chrome/test/app/signin_test_util.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 "ios/chrome/test/app/signin_test_util.h"
 
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #import "base/test/ios/wait_util.h"
 #include "components/prefs/pref_service.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "components/signin/core/common/signin_pref_names.h"
 #include "google_apis/gaia/gaia_constants.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/signin/account_tracker_service_factory.h"
 #import "ios/chrome/browser/signin/authentication_service.h"
 #include "ios/chrome/browser/signin/authentication_service_factory.h"
 #include "ios/chrome/browser/signin/gaia_auth_fetcher_ios.h"
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #import "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/test_url_fetcher_factory.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_status.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 net::FakeURLFetcherFactory* gFakeURLFetcherFactory = nullptr;
 
 // Specialization of the FakeURLFetcherFactory that will recognize GET requests
 // for MergeSession and answer those requests correctly.
 class MergeSessionFakeURLFetcherFactory : public net::FakeURLFetcherFactory {
  public:
   explicit MergeSessionFakeURLFetcherFactory(URLFetcherFactory* default_factory)
       : net::FakeURLFetcherFactory(default_factory) {}
@@ skipping 108 matching lines @@
     account_tracker->RemoveAccount(info.account_id);
   }
 
   // Clear last signed in user preference.
   browser_state->GetPrefs()->ClearPref(prefs::kGoogleServicesLastAccountId);
   browser_state->GetPrefs()->ClearPref(prefs::kGoogleServicesLastUsername);
 
   // Clear known identities.
   ios::ChromeIdentityService* identity_service =
       ios::GetChromeBrowserProvider()->GetChromeIdentityService();
-  base::scoped_nsobject<NSArray> identities(
-      [identity_service->GetAllIdentities() copy]);
-  for (ChromeIdentity* identity in identities.get()) {
+  NSArray* identities([identity_service->GetAllIdentities() copy]);
+  for (ChromeIdentity* identity in identities) {
     identity_service->ForgetIdentity(identity, nil);
   }
 
   NSDate* deadline = [NSDate dateWithTimeIntervalSinceNow:10.0];
   while (identity_service->HasIdentities() &&
          [[NSDate date] compare:deadline] != NSOrderedDescending) {
     base::test::ios::SpinRunLoopWithMaxDelay(
         base::TimeDelta::FromSecondsD(0.01));
   }
   return !identity_service->HasIdentities();
 }
 
 }  // namespace chrome_test_util