Fix unique_ptr usage in handling OAuth2TokenService::StartRequest result

components/signin/core/browser/child_account_info_fetcher_impl.cc

Index: components/signin/core/browser/child_account_info_fetcher_impl.cc
diff --git a/components/signin/core/browser/child_account_info_fetcher_impl.cc b/components/signin/core/browser/child_account_info_fetcher_impl.cc
index c8c2a78290af000325ce4f606db8e6bb6d64c572..1ada5f27b9beb45a09724a8f97c603eb447f3247 100644
--- a/components/signin/core/browser/child_account_info_fetcher_impl.cc
+++ b/components/signin/core/browser/child_account_info_fetcher_impl.cc
@@ -84,8 +84,8 @@ void ChildAccountInfoFetcherImpl::FetchIfNotInProgress() {
   fetch_in_progress_ = true;
   OAuth2TokenService::ScopeSet scopes;
   scopes.insert(GaiaConstants::kOAuth1LoginScope);
-  login_token_request_.reset(
-      token_service_->StartRequest(account_id_, scopes, this).release());
+  login_token_request_ =
+      token_service_->StartRequest(account_id_, scopes, this);
 }
 
 void ChildAccountInfoFetcherImpl::OnGetTokenSuccess(