Fix use-after-move in //chrome/browser/sharing/web_push/

Fix use-after-move (potential) bugs found by the
"bugprone-use-after-move" clang-tidy check.

Bug: 1122844
Change-Id: I2ac047515f09a14b7acb4ec36fd54d788d21a1a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2382814Reviewed-by: Alex Chau <alexchau@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803667}

chrome/browser/sharing/web_push/web_push_sender.cc

@@ -165,7 +165,8 @@ void WebPushSender::SendMessage(const std::string& fcm_token,
   std::unique_ptr<network::SimpleURLLoader> url_loader = BuildURLLoader(
       fcm_token, message.time_to_live, GetUrgencyHeader(message.urgency),
       *auth_header, message.payload);
-  url_loader->DownloadToString(
+  network::SimpleURLLoader* const url_loader_ptr = url_loader.get();
+  url_loader_ptr->DownloadToString(
       url_loader_factory_.get(),
       base::BindOnce(&WebPushSender::OnMessageSent,
                      weak_ptr_factory_.GetWeakPtr(), std::move(url_loader),