AttachmentDownloader implementation.

sync/internal_api/attachments/attachment_downloader_impl.cc

+// 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.
+
+#include "sync/internal_api/public/attachments/attachment_downloader_impl.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+
+namespace syncer {
+
+AttachmentDownloaderImpl::AttachmentDownloaderImpl() {
+}
+
+AttachmentDownloaderImpl::~AttachmentDownloaderImpl() {
+  DCHECK(CalledOnValidThread());
+}
+
+void AttachmentDownloaderImpl::DownloadAttachment(
+    const AttachmentId& attachment_id,
+    const DownloadCallback& callback) {
+  DCHECK(CalledOnValidThread());
+  // No real implementation yet. Fail every request with
+  // DOWNLOAD_UNSPECIFIED_ERROR.
+  scoped_ptr<Attachment> attachment;
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(
+          callback, DOWNLOAD_UNSPECIFIED_ERROR, base::Passed(&attachment)));
+}
+
+}  // namespace syncer