Revert of Refactor FakeAttachmentStore

sync/api/attachments/attachment_store.cc

Index: sync/api/attachments/attachment_store.cc
diff --git a/sync/api/attachments/attachment_store.cc b/sync/api/attachments/attachment_store.cc
index ad4489e8d8db63b1d376b75d94fedc803599614f..e22b040e3dec3e691b35179b5dc3bae05bb18927 100644
--- a/sync/api/attachments/attachment_store.cc
+++ b/sync/api/attachments/attachment_store.cc
@@ -4,24 +4,9 @@
 
 #include "sync/api/attachments/attachment_store.h"
 
-#include "base/thread_task_runner_handle.h"
-#include "sync/internal_api/public/attachments/attachment_store_handle.h"
-#include "sync/internal_api/public/attachments/in_memory_attachment_store.h"
-
 namespace syncer {
-
-AttachmentStoreBase::AttachmentStoreBase() {}
-AttachmentStoreBase::~AttachmentStoreBase() {}
 
 AttachmentStore::AttachmentStore() {}
 AttachmentStore::~AttachmentStore() {}
 
-scoped_refptr<AttachmentStore> AttachmentStore::CreateInMemoryStore() {
-  // Both frontend and backend of attachment store will live on current thread.
-  scoped_ptr<AttachmentStoreBase> backend(
-      new InMemoryAttachmentStore(base::ThreadTaskRunnerHandle::Get()));
-  return scoped_refptr<AttachmentStore>(new AttachmentStoreHandle(
-      backend.Pass(), base::ThreadTaskRunnerHandle::Get()));
-}
-
 }  // namespace syncer