[Sync] Move attachments code out of core/.

components/sync/core/attachments/fake_attachment_uploader.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 COMPONENTS_SYNC_CORE_ATTACHMENTS_FAKE_ATTACHMENT_UPLOADER_H_
-#define COMPONENTS_SYNC_CORE_ATTACHMENTS_FAKE_ATTACHMENT_UPLOADER_H_
-
-#include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
-#include "components/sync/core/attachments/attachment_uploader.h"
-
-namespace syncer {
-
-// A fake implementation of AttachmentUploader.
-class FakeAttachmentUploader : public AttachmentUploader,
-                               public base::NonThreadSafe {
- public:
-  FakeAttachmentUploader();
-  ~FakeAttachmentUploader() override;
-
-  // AttachmentUploader implementation.
-  void UploadAttachment(const Attachment& attachment,
-                        const UploadCallback& callback) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(FakeAttachmentUploader);
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_SYNC_CORE_ATTACHMENTS_FAKE_ATTACHMENT_UPLOADER_H_