Refactor FakeAttachmentStore

sync/internal_api/public/attachments/in_memory_attachment_store.h

Index: sync/internal_api/public/attachments/in_memory_attachment_store.h
diff --git a/sync/internal_api/public/attachments/in_memory_attachment_store.h b/sync/internal_api/public/attachments/in_memory_attachment_store.h
new file mode 100644
index 0000000000000000000000000000000000000000..06a982bb224a309aa9798bd5d077dbb0e4af903e
--- /dev/null
+++ b/sync/internal_api/public/attachments/in_memory_attachment_store.h
@@ -0,0 +1,43 @@
+// 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_INTERNAL_API_PUBLIC_ATTACHMENTS_IN_MEMORY_ATTACHMENT_STORE_H_
+#define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_IN_MEMORY_ATTACHMENT_STORE_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/non_thread_safe.h"
+#include "sync/api/attachments/attachment.h"
+#include "sync/api/attachments/attachment_id.h"
+#include "sync/api/attachments/attachment_store.h"
+#include "sync/base/sync_export.h"
+
+namespace syncer {
+
+// An in-memory implementation of AttachmentStore used for testing.
+// InMemoryAttachmentStore is not threadsafe, it lives on backend thread and
+// posts callbacks with results on |callback_task_runner|.
+class SYNC_EXPORT InMemoryAttachmentStore : public AttachmentStoreBase,
+                                            public base::NonThreadSafe {
+ public:
+  InMemoryAttachmentStore(
+      const scoped_refptr<base::SingleThreadTaskRunner>& callback_task_runner);
+  virtual ~InMemoryAttachmentStore();
+
+  // AttachmentStoreBase implementation.
+  virtual void Read(const AttachmentIdList& ids,
+                    const ReadCallback& callback) OVERRIDE;
+  virtual void Write(const AttachmentList& attachments,
+                     const WriteCallback& callback) OVERRIDE;
+  virtual void Drop(const AttachmentIdList& ids,
+                    const DropCallback& callback) OVERRIDE;
+
+ private:
+  scoped_refptr<base::SingleThreadTaskRunner> callback_task_runner_;
+  AttachmentMap attachments_;
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_IN_MEMORY_ATTACHMENT_STORE_H_