Introduce a layering in the invalidation component as public and impl

components/invalidation/impl/invalidator_registrar.h

Index: components/invalidation/impl/invalidator_registrar.h
diff --git a/components/invalidation/invalidator_registrar.h b/components/invalidation/impl/invalidator_registrar.h
similarity index 90%
rename from components/invalidation/invalidator_registrar.h
rename to components/invalidation/impl/invalidator_registrar.h
index 9acf26c0a0b779f56bbbe90fe92594323f6087f5..741676cbfe3dde492aef958b24758cece8cf4ccc 100644
--- a/components/invalidation/invalidator_registrar.h
+++ b/components/invalidation/impl/invalidator_registrar.h
@@ -2,17 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_INVALIDATION_INVALIDATOR_REGISTRAR_H_
-#define COMPONENTS_INVALIDATION_INVALIDATOR_REGISTRAR_H_
+#ifndef COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_REGISTRAR_H_
+#define COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_REGISTRAR_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
-#include "components/invalidation/invalidation_export.h"
-#include "components/invalidation/invalidation_handler.h"
-#include "components/invalidation/invalidation_util.h"
+#include "components/invalidation/public/invalidation_export.h"
+#include "components/invalidation/public/invalidation_handler.h"
+#include "components/invalidation/public/invalidation_util.h"
 
 namespace invalidation {
 class ObjectId;
@@ -94,4 +94,4 @@ class INVALIDATION_EXPORT InvalidatorRegistrar {
 
 }  // namespace syncer
 
-#endif  // COMPONENTS_INVALIDATION_INVALIDATOR_REGISTRAR_H_
+#endif  // COMPONENTS_INVALIDATION_IMPL_INVALIDATOR_REGISTRAR_H_