Revert of Refactor FakeAttachmentStore

sync/api/attachments/fake_attachment_store.h

+// Copyright 2014 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 SYNC_API_ATTACHMENTS_FAKE_ATTACHMENT_STORE_H_
+#define SYNC_API_ATTACHMENTS_FAKE_ATTACHMENT_STORE_H_
+
+#include <map>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/stl_util.h"
+#include "sync/api/attachments/attachment_store.h"
+#include "sync/base/sync_export.h"
+
+namespace base {
+class SequencedTaskRunner;
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace sync_pb {
+class AttachmentId;
+}  // namespace sync_pb
+
+namespace syncer {
+
+class Attachment;
+
+// A in-memory only implementation of AttachmentStore used for testing.
+//
+// Requires that the current thread has a MessageLoop.
+class SYNC_EXPORT FakeAttachmentStore : public AttachmentStore {
+ public:
+  // Construct a FakeAttachmentStore whose "IO" will be performed in
+  // |backend_task_runner|.
+  explicit FakeAttachmentStore(
+      const scoped_refptr<base::SequencedTaskRunner>& backend_task_runner);
+
+  // AttachmentStore implementation.
+  virtual void Read(const AttachmentIdList& id,
+                    const ReadCallback& callback) OVERRIDE;
+  virtual void Write(const AttachmentList& attachments,
+                     const WriteCallback& callback) OVERRIDE;
+  virtual void Drop(const AttachmentIdList& id,
+                    const DropCallback& callback) OVERRIDE;
+
+ private:
+  class Backend;
+
+  virtual ~FakeAttachmentStore();
+
+  scoped_refptr<Backend> backend_;
+  scoped_refptr<base::SequencedTaskRunner> backend_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeAttachmentStore);
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_API_ATTACHMENTS_FAKE_ATTACHMENT_STORE_H_