Revert of Moving previews code from components/ to chrome/

components/previews/core/previews_opt_out_store_sql.h

Index: components/previews/core/previews_opt_out_store_sql.h
diff --git a/components/previews/core/previews_opt_out_store_sql.h b/components/previews/core/previews_opt_out_store_sql.h
index 0d3b6389e0f098b58910248d4ad510054910aab3..801b85074471063f309ce6d88dc9254a862af51b 100644
--- a/components/previews/core/previews_opt_out_store_sql.h
+++ b/components/previews/core/previews_opt_out_store_sql.h
@@ -36,8 +36,7 @@
   PreviewsOptOutStoreSQL(
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       scoped_refptr<base::SequencedTaskRunner> background_task_runner,
-      const base::FilePath& database_dir,
-      std::unique_ptr<PreviewsTypeList> enabled_previews);
+      const base::FilePath& database_dir);
   ~PreviewsOptOutStoreSQL() override;
 
   // PreviewsOptOutStore implementation:
@@ -61,9 +60,6 @@
   // SQL connection to the SQLite database.
   std::unique_ptr<sql::Connection> db_;
 
-  // All enabled previews and versions.
-  const std::unique_ptr<PreviewsTypeList> enabled_previews_;
-
   DISALLOW_COPY_AND_ASSIGN(PreviewsOptOutStoreSQL);
 };