Adding unit tests for PreviewsOptOutStoreSQL

components/previews/core/previews_black_list_item.h

 // 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.
 
 #ifndef COMPONENTS_PREVIEWS_CORE_PREVIEWS_BLACK_LIST_ITEM_H_
 #define COMPONENTS_PREVIEWS_CORE_PREVIEWS_BLACK_LIST_ITEM_H_
 
 #include <stdint.h>
 
 #include <list>
@@ skipping 26 matching lines @@
   void AddPreviewNavigation(bool opt_out, base::Time entry_time);
 
   // Whether the host name corresponding to |this| should be disallowed from
   // showing previews.
   bool IsBlackListed(base::Time now) const;
 
   base::Optional<base::Time> most_recent_opt_out_time() const {
     return most_recent_opt_out_time_;
   }
 
+  size_t OptOutRecordsSizeForTesting() const;
+
  private:
   // A previews navigation to this host is represented by time and whether the
   // navigation was an opt out.
   struct OptOutRecord {
     OptOutRecord(base::Time entry_time, bool opt_out);
     ~OptOutRecord() {}
     const base::Time
         entry_time;      // The time that the opt out state was determined.
     const bool opt_out;  // Whether the user opt out of the preview.
   };
@@ skipping 14 matching lines @@
 
   // The total number of opt outs currently in |opt_out_records_|.
   int total_opt_out_;
 
   DISALLOW_COPY_AND_ASSIGN(PreviewsBlackListItem);
 };
 
 }  // namespace previews
 
 #endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_BLACK_LIST_ITEM_H_