[Sync] SyncEngine refactor part 1: interfaces.

components/sync/driver/glue/sync_backend_host.cc

Index: components/sync/driver/glue/sync_backend_host.cc
diff --git a/components/sync/driver/glue/sync_backend_host.cc b/components/sync/driver/glue/sync_backend_host.cc
deleted file mode 100644
index 76da557deb762a7c3b3e532d8fb4553f96b2dbc9..0000000000000000000000000000000000000000
--- a/components/sync/driver/glue/sync_backend_host.cc
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2012 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 "components/sync/driver/glue/sync_backend_host.h"
-
-namespace syncer {
-
-SyncBackendHost::SyncBackendHost() {}
-
-SyncBackendHost::~SyncBackendHost() {}
-
-}  // namespace syncer