Introduce a layering in the invalidation component as public and impl

components/invalidation/public/invalidation.h

 // 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.
 
-#ifndef COMPONENTS_INVALIDATION_INVALIDATION_H_
-#define COMPONENTS_INVALIDATION_INVALIDATION_H_
+#ifndef COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_
+#define COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "base/values.h"
-#include "components/invalidation/ack_handle.h"
-#include "components/invalidation/invalidation_export.h"
+#include "components/invalidation/public/ack_handle.h"
+#include "components/invalidation/public/invalidation_export.h"
 #include "google/cacheinvalidation/include/types.h"
 
 namespace syncer {
 
 class DroppedInvalidationTracker;
 class AckHandler;
 
 // Represents a local invalidation, and is roughly analogous to
 // invalidation::Invalidation.  Unlike invalidation::Invalidation, this class
 // supports "local" ack-tracking and simple serialization to pref values.
@@ skipping 90 matching lines @@
   // A locally generated unique ID used to manage local acknowledgements.
   AckHandle ack_handle_;
 
   // The acknowledgement tracking handler and its thread.
   base::WeakPtr<AckHandler> ack_handler_;
   scoped_refptr<base::SequencedTaskRunner> ack_handler_task_runner_;
 };
 
 }  // namespace syncer
 
-#endif  // COMPONENTS_INVALIDATION_INVALIDATION_H_
+#endif  // COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_