Changed previews component to be a layered component.

components/previews/core/previews_ui_service.cc

 // Copyright 2016 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/previews/previews_ui_service.h"
+#include "components/previews/core/previews_ui_service.h"
 
-#include "components/previews/previews_io_data.h"
+#include "components/previews/core/previews_io_data.h"
 
 namespace previews {
 
 PreviewsUIService::PreviewsUIService(
     PreviewsIOData* previews_io_data,
     const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
     : io_task_runner_(io_task_runner), weak_factory_(this) {
   previews_io_data->Initialize(weak_factory_.GetWeakPtr());
 }
 
 PreviewsUIService::~PreviewsUIService() {
   DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void PreviewsUIService::SetIOData(base::WeakPtr<PreviewsIOData> io_data) {
   DCHECK(thread_checker_.CalledOnValidThread());
   io_data_ = io_data;
 }
 
 }  // namespace previews