[Offline pages] Updating RequestQueue::RemoveRequests to use a TaskQueue

components/offline_pages/background/remove_requests_task.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_OFFLINE_PAGES_BACKGROUND_REMOVE_REQUESTS_TASK_H_
+#define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REMOVE_REQUESTS_TASK_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "base/memory/weak_ptr.h"
+#include "components/offline_pages/background/request_queue_store.h"
+#include "components/offline_pages/background/save_page_request.h"
+#include "components/offline_pages/core/task.h"
+
+namespace offline_pages {
+
+class RemoveRequestsTask : public Task {
+ public:
+  RemoveRequestsTask(RequestQueueStore* store,
+                     const std::vector<int64_t>& request_ids,
+                     const RequestQueueStore::UpdateCallback& callback);
+  ~RemoveRequestsTask() override;
+
+  // TaskQueue::Task implementation.
+  void Run() override;
+
+ private:
+  // Step 1. Removes requests from the store.
+  void RemoveRequests();
+  // Step for early termination, that builds failure result.
+  void CompleteEarly(ItemActionStatus status);
+  // Step 2. Processes update result, calls callback.
+  void CompleteWithResult(std::unique_ptr<UpdateRequestsResult> result);
+
+  // Store that this task updates.
+  RequestQueueStore* store_;
+  // Request IDs to be updated.
+  // TODO(fgorski): perhaps convert to unique_ptr to a vector.
+  std::vector<int64_t> request_ids_;
+  // Callback to complete the task.
+  RequestQueueStore::UpdateCallback callback_;
+
+  base::WeakPtrFactory<RemoveRequestsTask> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemoveRequestsTask);
+};
+
+}  // namespace offline_pages
+
+#endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REMOVE_REQUESTS_TASK_H_