Upstream Chrome on iOS source code [5/11].

ios/chrome/browser/ui/history/history_service_facade_delegate.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 IOS_CHROME_BROWSER_UI_HISTORY_HISTORY_SERVICE_FACADE_DELEGATE_H_
+#define IOS_CHROME_BROWSER_UI_HISTORY_HISTORY_SERVICE_FACADE_DELEGATE_H_
+
+#include "ios/chrome/browser/ui/history/history_service_facade.h"
+
+// Delegate for HistoryServiceFacade. Defines methods to manage history query
+// results and deletion actions.
+@protocol HistoryServiceFacadeDelegate<NSObject>
+
+@optional
+
+// Notifies the delegate that the result of a history query has been retrieved.
+// Entries in |result| are already sorted.
+- (void)historyServiceFacade:(HistoryServiceFacade*)facade
+       didReceiveQueryResult:(HistoryServiceFacade::QueryResult)result;
+
+// Notifies the delegate that history entries have been deleted by a different
+// client and that the UI should be updated.
+- (void)historyServiceFacadeDidObserveHistoryDeletion:
+    (HistoryServiceFacade*)facade;
+
+// Indicates to the delegate whether to show notice about other forms of
+// browsing history.
+- (void)historyServiceFacade:(HistoryServiceFacade*)facade
+    shouldShowNoticeAboutOtherFormsOfBrowsingHistory:(BOOL)shouldShowNotice;
+
+// Notifies the delegate that history entry deletion has completed.
+- (void)historyServiceFacadeDidCompleteEntryRemoval:
+    (HistoryServiceFacade*)facade;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_HISTORY_HISTORY_SERVICE_FACADE_DELEGATE_H_