Introduce a layering in the invalidation component as public and impl

components/invalidation/base/ack_handle.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_ACK_HANDLE_H_
-#define COMPONENTS_INVALIDATION_ACK_HANDLE_H_
+#ifndef COMPONENTS_INVALIDATION_BASE_ACK_HANDLE_H_
+#define COMPONENTS_INVALIDATION_BASE_ACK_HANDLE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
-#include "components/invalidation/invalidation_export.h"
+#include "components/invalidation/base/invalidation_export.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace syncer {
 
 // Opaque class that represents a local ack handle. We don't reuse the
 // invalidation ack handles to avoid unnecessary dependencies.
 class INVALIDATION_EXPORT AckHandle {
@@ skipping 13 matching lines @@
  private:
   // Explicitly copyable and assignable for STL containers.
   AckHandle(const std::string& state, base::Time timestamp);
 
   std::string state_;
   base::Time timestamp_;
 };
 
 }  // namespace syncer
 
-#endif  // COMPONENTS_INVALIDATION_ACK_HANDLE_H_
+#endif  // COMPONENTS_INVALIDATION_BASE_ACK_HANDLE_H_