[ObjC ARC] Converts ios/chrome/browser/signin:signin to ARC.

ios/chrome/browser/signin/browser_state_data_remover.mm

 // Copyright 2014 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 "ios/chrome/browser/signin/browser_state_data_remover.h"
 
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/prefs/pref_service.h"
 #include "components/signin/core/common/signin_pref_names.h"
 #include "ios/chrome/browser/bookmarks/bookmarks_utils.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/reading_list/reading_list_remover_helper.h"
 #import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
 #import "ios/chrome/browser/ui/commands/clear_browsing_data_command.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 const int kRemoveAllDataMask = ~0;
 }
 
 BrowserStateDataRemover::BrowserStateDataRemover(
     ios::ChromeBrowserState* browser_state)
     : browser_state_(browser_state), forget_last_username_(false) {
   callback_subscription_ =
       IOSChromeBrowsingDataRemover::RegisterOnBrowsingDataRemovedCallback(
           base::Bind(&BrowserStateDataRemover::NotifyWithDetails,
@@ skipping 15 matching lines @@
 }
 
 void BrowserStateDataRemover::SetForgetLastUsername() {
   forget_last_username_ = true;
 }
 
 void BrowserStateDataRemover::RemoveBrowserStateData(ProceduralBlock callback) {
   DCHECK(!callback_);
   callback_.reset([callback copy]);
 
-  base::scoped_nsobject<ClearBrowsingDataCommand> command(
-      [[ClearBrowsingDataCommand alloc]
-          initWithBrowserState:browser_state_
-                          mask:kRemoveAllDataMask
-                    timePeriod:browsing_data::TimePeriod::ALL_TIME]);
+  ClearBrowsingDataCommand* command = [[ClearBrowsingDataCommand alloc]
+      initWithBrowserState:browser_state_
+                      mask:kRemoveAllDataMask
+                timePeriod:browsing_data::TimePeriod::ALL_TIME];
 
   UIWindow* mainWindow = [[UIApplication sharedApplication] keyWindow];
   DCHECK(mainWindow);
   [mainWindow chromeExecuteCommand:command];
 }
 
 void BrowserStateDataRemover::NotifyWithDetails(
     const IOSChromeBrowsingDataRemover::NotificationDetails& details) {
   // Remove bookmarks and Reading List entriesonce all browsing data was
   // removed.
@@ skipping 23 matching lines @@
   if (forget_last_username_) {
     browser_state_->GetPrefs()->ClearPref(prefs::kGoogleServicesLastAccountId);
     browser_state_->GetPrefs()->ClearPref(prefs::kGoogleServicesLastUsername);
   }
 
   if (callback_)
     callback_.get()();
 
   base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this);
 }