Revert of [Sync] Refactor AttachmentStore classes. Introduce concept of referrer.

sync/sync.gyp

 # Copyright 2013 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
 
   'includes': [
@@ skipping 49 matching lines @@
       ],
       'sources': [
         'api/attachments/attachment.cc',
         'api/attachments/attachment.h',
         'api/attachments/attachment_id.cc',
         'api/attachments/attachment_id.h',
         'api/attachments/attachment_metadata.cc',
         'api/attachments/attachment_metadata.h',
         'api/attachments/attachment_store.cc',
         'api/attachments/attachment_store.h',
-        'api/attachments/attachment_store_backend.cc',
-        'api/attachments/attachment_store_backend.h',
         'api/string_ordinal.h',
         'api/sync_change.cc',
         'api/sync_change.h',
         'api/sync_change_processor.cc',
         'api/sync_change_processor.h',
         'api/sync_data.cc',
         'api/sync_data.h',
         'api/sync_error.cc',
         'api/sync_error.h',
         'api/sync_error_factory.cc',
@@ skipping 80 matching lines @@
         'engine/update_applicator.cc',
         'engine/update_applicator.h',
         'engine/update_handler.cc',
         'engine/update_handler.h',
         'internal_api/attachments/attachment_downloader.cc',
         'internal_api/attachments/attachment_downloader_impl.cc',
         'internal_api/attachments/attachment_service.cc',
         'internal_api/attachments/attachment_service_impl.cc',
         'internal_api/attachments/attachment_service_proxy.cc',
         'internal_api/attachments/attachment_service_proxy_for_test.cc',
-        'internal_api/attachments/attachment_store_frontend.cc',
+        'internal_api/attachments/attachment_store_handle.cc',
         'internal_api/attachments/attachment_uploader.cc',
         'internal_api/attachments/attachment_uploader_impl.cc',
         'internal_api/attachments/attachment_util.cc',
         'internal_api/attachments/fake_attachment_downloader.cc',
         'internal_api/attachments/fake_attachment_uploader.cc',
         'internal_api/attachments/in_memory_attachment_store.cc',
         'internal_api/attachments/on_disk_attachment_store.cc',
         'internal_api/attachments/task_queue.cc',
         'internal_api/base_node.cc',
         'internal_api/base_transaction.cc',
@@ skipping 20 matching lines @@
         'internal_api/js_sync_manager_observer.cc',
         'internal_api/js_sync_manager_observer.h',
         'internal_api/protocol_event_buffer.cc',
         'internal_api/protocol_event_buffer.h',
         'internal_api/public/attachments/attachment_downloader.h',
         'internal_api/public/attachments/attachment_downloader_impl.h',
         'internal_api/public/attachments/attachment_service.h',
         'internal_api/public/attachments/attachment_service_impl.h',
         'internal_api/public/attachments/attachment_service_proxy.h',
         'internal_api/public/attachments/attachment_service_proxy_for_test.h',
-        'internal_api/public/attachments/attachment_store_frontend.h',
+        'internal_api/public/attachments/attachment_store_handle.h',
         'internal_api/public/attachments/attachment_uploader.h',
         'internal_api/public/attachments/attachment_uploader_impl.h',
         'internal_api/public/attachments/attachment_util.h',
         'internal_api/public/attachments/fake_attachment_downloader.h',
         'internal_api/public/attachments/fake_attachment_uploader.h',
         'internal_api/public/attachments/in_memory_attachment_store.h',
         'internal_api/public/attachments/on_disk_attachment_store.h',
         'internal_api/public/attachments/task_queue.h',
         'internal_api/public/base/attachment_id_proto.cc',
         'internal_api/public/base/attachment_id_proto.h',
@@ skipping 322 matching lines @@
       },
       'includes': [
         '../build/protoc.gypi'
       ],
       'defines': [
         'SYNC_IMPLEMENTATION'
       ],
     },
   ],
 }