Ensure metrics for Invalid Url report on failed mount

Fixes a bug where metrics were not recorded correctly for failed mounts
due to invalid urls.

Bug: chromium:902923
Change-Id: Iba8164d4869818a44faa10ee18503cdd1e24d424
Reviewed-on: https://chromium-review.googlesource.com/c/1340971Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609052}

chrome/browser/chromeos/smb_client/smb_service.cc

@@ -190,7 +190,8 @@ void SmbService::CallMount(const file_system_provider::MountOptions& options,
 
   SmbUrl parsed_url(share_path.value());
   if (!parsed_url.IsValid()) {
-    std::move(callback).Run(
+    FireMountCallback(
+        std::move(callback),
         TranslateErrorToMountResult(base::File::Error::FILE_ERROR_INVALID_URL));
     return;
   }