Adding ClearBlackList to the PreviewsBlackList and plumbing to UI

components/previews/core/previews_opt_out_store.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_OPT_OUT_STORE_H_
 #define COMPONENTS_PREVIEWS_CORE_PREVIEWS_OPT_OUT_STORE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 33 matching lines @@
   // Adds a new navigation to the store. |opt_out| is whether the user opted out
   // of the preview.
   virtual void AddPreviewNavigation(bool opt_out,
                                     const std::string& host_name,
                                     PreviewsType type,
                                     base::Time now) = 0;
 
   // Asynchronously loads a map of host names to PreviewsBlackListItem for that
   // host from the store. And runs |callback| once loading is finished.
   virtual void LoadBlackList(LoadBlackListCallback callback) = 0;
+
+  // Deletes all history in the store between |begin_time| and |end_time|.
+  virtual void ClearBlackList(base::Time begin_time, base::Time end_time) = 0;
 };
 
 }  // namespace previews
 
 #endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_OPT_OUT_STORE_H_