[ObjC ARC] Converts ios/chrome/browser/browser_state:browser_state_impl.

ios/chrome/browser/browser_state/chrome_browser_state_removal_controller.mm

 // Copyright 2015 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/browser/browser_state/chrome_browser_state_removal_controller.h"
 
 #import <Foundation/Foundation.h>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/prefs/pref_service.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/browser_state/browser_state_info_cache.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state_manager.h"
 #include "ios/chrome/browser/chrome_constants.h"
 #include "ios/chrome/browser/chrome_paths_internal.h"
 #include "ios/chrome/browser/pref_names.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #import "ios/public/provider/chrome/browser/signin/chrome_identity.h"
 #include "ios/public/provider/chrome/browser/signin/chrome_identity_service.h"
 #include "ios/web/public/web_thread.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 ChromeBrowserStateRemovalController* g_chrome_browser_state_removal_helper =
     nullptr;
 
 NSString* const kPathToBrowserStateToKeepKey = @"PathToBrowserStateToKeep";
 NSString* const kHasBrowserStateBeenRemovedKey = @"HasBrowserStateBeenRemoved";
 
 const char kGmailDomain[] = "gmail.com";
 
@@ skipping 126 matching lines @@
 std::string ChromeBrowserStateRemovalController::GetLastBrowserStatePathUsed() {
   return GetApplicationContext()->GetLocalState()->GetString(
       prefs::kBrowserStateLastUsed);
 }
 
 void ChromeBrowserStateRemovalController::SetLastBrowserStatePathUsed(
     const std::string& browser_state_path) {
   GetApplicationContext()->GetLocalState()->SetString(
       prefs::kBrowserStateLastUsed, browser_state_path);
 }