Clean up ARC file system unit tests.

components/arc/file_system/test/fake_arc_file_system_operation_runner.h

-// Copyright 2017 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_ARC_FILE_SYSTEM_FAKE_ARC_FILE_SYSTEM_OPERATION_RUNNER_H_
-#define COMPONENTS_ARC_FILE_SYSTEM_FAKE_ARC_FILE_SYSTEM_OPERATION_RUNNER_H_
-
-#include "base/macros.h"
-#include "components/arc/file_system/arc_file_system_operation_runner.h"
-
-namespace arc {
-
-// TODO(crbug.com/683049): Implement a generic fake.
-class FakeArcFileSystemOperationRunner : public ArcFileSystemOperationRunner {
- public:
-  explicit FakeArcFileSystemOperationRunner(ArcBridgeService* bridge_service);
-  ~FakeArcFileSystemOperationRunner() override;
-
-  // ArcFileSystemOperationRunner overrides.
-  void GetFileSize(const GURL& url,
-                   const GetFileSizeCallback& callback) override;
-  void OpenFileToRead(const GURL& url,
-                      const OpenFileToReadCallback& callback) override;
-  void GetDocument(const std::string& authority,
-                   const std::string& document_id,
-                   const GetDocumentCallback& callback) override;
-  void GetChildDocuments(const std::string& authority,
-                         const std::string& parent_document_id,
-                         const GetChildDocumentsCallback& callback) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(FakeArcFileSystemOperationRunner);
-};
-
-}  // namespace arc
-
-#endif  // COMPONENTS_ARC_FILE_SYSTEM_FAKE_ARC_FILE_SYSTEM_OPERATION_RUNNER_H_