Introduce a layering in the invalidation component as public and impl

components/invalidation/invalidator_registrar.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 "components/invalidation/invalidator_registrar.h"
 
 #include <cstddef>
 #include <iterator>
 #include <utility>
 
 #include "base/logging.h"
-#include "components/invalidation/object_id_invalidation_map.h"
+#include "components/invalidation/base/object_id_invalidation_map.h"
 
 namespace syncer {
 
 InvalidatorRegistrar::InvalidatorRegistrar()
     : state_(DEFAULT_INVALIDATION_ERROR) {}
 
 InvalidatorRegistrar::~InvalidatorRegistrar() {
   DCHECK(thread_checker_.CalledOnValidThread());
   CHECK(handler_to_ids_map_.empty());
 }
@@ skipping 118 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   return handlers_.HasObserver(handler);
 }
 
 void InvalidatorRegistrar::DetachFromThreadForTest() {
   DCHECK(thread_checker_.CalledOnValidThread());
   thread_checker_.DetachFromThread();
 }
 
 }  // namespace syncer