Introduce a layering in the invalidation component as public and impl

sync/tools/null_invalidation_state_tracker.cc

 // Copyright (c) 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 "sync/tools/null_invalidation_state_tracker.h"
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/task_runner.h"
-#include "components/invalidation/invalidation_util.h"
+#include "components/invalidation/public/invalidation_util.h"
 
 namespace syncer {
 
 NullInvalidationStateTracker::NullInvalidationStateTracker() {}
 NullInvalidationStateTracker::~NullInvalidationStateTracker() {}
 
 void NullInvalidationStateTracker::ClearAndSetNewClientId(
     const std::string& data) {
   LOG(INFO) << "Setting invalidator client ID to: " << data;
 }
@@ skipping 26 matching lines @@
     const UnackedInvalidationsMap& states) {
   // Do nothing.
 }
 
 UnackedInvalidationsMap
 NullInvalidationStateTracker::GetSavedInvalidations() const {
   return UnackedInvalidationsMap();
 }
 
 }  // namespace syncer