Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/signin/account_consistency_service_factory.mm

Index: ios/chrome/browser/signin/account_consistency_service_factory.mm
diff --git a/ios/chrome/browser/signin/account_consistency_service_factory.mm b/ios/chrome/browser/signin/account_consistency_service_factory.mm
index f01e0e8191b041600aaf76f8f524f1e612eb831a..f3a9818be2c30a4214171986ec88cdcc9d808be4 100644
--- a/ios/chrome/browser/signin/account_consistency_service_factory.mm
+++ b/ios/chrome/browser/signin/account_consistency_service_factory.mm
@@ -4,6 +4,7 @@
 
 #include "ios/chrome/browser/signin/account_consistency_service_factory.h"
 
+#include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "components/signin/ios/browser/account_consistency_service.h"
@@ -47,12 +48,12 @@ void AccountConsistencyServiceFactory::RegisterBrowserStatePrefs(
   AccountConsistencyService::RegisterPrefs(registry);
 }
 
-scoped_ptr<KeyedService>
+std::unique_ptr<KeyedService>
 AccountConsistencyServiceFactory::BuildServiceInstanceFor(
     web::BrowserState* context) const {
   ios::ChromeBrowserState* chrome_browser_state =
       ios::ChromeBrowserState::FromBrowserState(context);
-  return make_scoped_ptr(new AccountConsistencyService(
+  return base::WrapUnique(new AccountConsistencyService(
       chrome_browser_state,
       ios::AccountReconcilorFactory::GetForBrowserState(chrome_browser_state),
       ios::CookieSettingsFactory::GetForBrowserState(chrome_browser_state),