Instantiate AttachmentDownloader and use it in AttachmentServiceImpl

sync/api/attachments/attachment_service_impl.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_ATTACHMENT_SERVICE_IMPL_H_
 #define SYNC_API_ATTACHMENTS_ATTACHMENT_SERVICE_IMPL_H_
 
+#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
+#include "sync/api/attachments/attachment_downloader.h"
 #include "sync/api/attachments/attachment_service.h"
 #include "sync/api/attachments/attachment_service_proxy.h"
 #include "sync/api/attachments/attachment_store.h"
 #include "sync/api/attachments/attachment_uploader.h"
 
 namespace syncer {
 
 // Implementation of AttachmentService.
 class SYNC_EXPORT AttachmentServiceImpl : public AttachmentService,
                                           public base::NonThreadSafe {
  public:
   // |delegate| is optional delegate for AttachmentService to notify about
   // asynchronous events (AttachmentUploaded). Pass NULL if delegate is not
   // provided. AttachmentService doesn't take ownership of delegate, the pointer
   // must be valid throughout AttachmentService lifetime.
   AttachmentServiceImpl(scoped_ptr<AttachmentStore> attachment_store,
                         scoped_ptr<AttachmentUploader> attachment_uploader,
+                        scoped_ptr<AttachmentDownloader> attachment_downloader,
                         Delegate* delegate);
   virtual ~AttachmentServiceImpl();
 
   // Create an AttachmentServiceImpl suitable for use in tests.
   static scoped_ptr<syncer::AttachmentService> CreateForTest();
 
   // AttachmentService implementation.
   virtual void GetOrDownloadAttachments(const AttachmentIdList& attachment_ids,
                                         const GetOrDownloadCallback& callback)
       OVERRIDE;
   virtual void DropAttachments(const AttachmentIdList& attachment_ids,
                                const DropCallback& callback) OVERRIDE;
   virtual void StoreAttachments(const AttachmentList& attachments,
                                 const StoreCallback& callback) OVERRIDE;
   virtual void OnSyncDataDelete(const SyncData& sync_data) OVERRIDE;
   virtual void OnSyncDataUpdate(const AttachmentIdList& old_attachment_ids,
                                 const SyncData& updated_sync_data) OVERRIDE;
 
  private:
-  void ReadDone(const GetOrDownloadCallback& callback,
+  class GetOrDownloadState;
+
+  void ReadDone(const scoped_refptr<GetOrDownloadState>& state,
                 const AttachmentStore::Result& result,
                 scoped_ptr<AttachmentMap> attachments,
                 scoped_ptr<AttachmentIdList> unavailable_attachment_ids);
   void DropDone(const DropCallback& callback,
                 const AttachmentStore::Result& result);
   void WriteDone(const StoreCallback& callback,
                  const AttachmentStore::Result& result);
   void UploadDone(const AttachmentUploader::UploadResult& result,
                   const AttachmentId& attachment_id);
+  void DownloadDone(const scoped_refptr<GetOrDownloadState>& state,
+                    const AttachmentId& attachment_id,
+                    const AttachmentDownloader::DownloadResult& result,
+                    scoped_ptr<Attachment> attachment);
 
   const scoped_ptr<AttachmentStore> attachment_store_;
   const scoped_ptr<AttachmentUploader> attachment_uploader_;
+  const scoped_ptr<AttachmentDownloader> attachment_downloader_;
   Delegate* delegate_;
   // Must be last data member.
   base::WeakPtrFactory<AttachmentServiceImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AttachmentServiceImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_API_ATTACHMENTS_ATTACHMENT_SERVICE_IMPL_H_