Fix use-after-move in //c/b/chromeos/file_system_provider/

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

Bug: 1122844
Change-Id: I0f225f57e701f19705e46e5594528b5f1a82a56d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2555419
Commit-Queue: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Auto-Submit: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Reviewed-by: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830489}

chrome/browser/chromeos/file_system_provider/queue.cc

@@ -65,15 +65,16 @@ void Queue::MaybeRun() {
 
   CHECK_GT(max_in_parallel_, executed_.size());
   Task task = std::move(pending_.front());
+  const size_t token = task.token;
   pending_.pop_front();
 
   auto callback = std::move(task.callback);
-  executed_[task.token] = std::move(task);
+  executed_[token] = std::move(task);
   AbortCallback abort_callback = std::move(callback).Run();
 
   // It may happen that the task is completed and removed synchronously. Hence,
   // we need to check if the task is still in the executed collection.
-  const auto executed_task_it = executed_.find(task.token);
+  const auto executed_task_it = executed_.find(token);
   if (executed_task_it != executed_.end())
     executed_task_it->second.abort_callback = std::move(abort_callback);
 }