[LanguageModel] Clear the model when clearing full history

components/translate/core/browser/language_model.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_TRANSLATE_CORE_BROWSER_LANGUAGE_MODEL_H_
 #define COMPONENTS_TRANSLATE_CORE_BROWSER_LANGUAGE_MODEL_H_
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/time/time.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace translate {
 
 // Collects data about languages in which the user reads the web and provides
 // access to current estimated language preferences. The past behaviour is
 // discounted so that this model reflects changes in browsing habits. This model
@@ skipping 27 matching lines @@
   // enough data points.
   std::vector<LanguageInfo> GetTopLanguages() const;
 
   // Returns the estimated frequency for the given language or 0 if the language
   // is not among the top languages kept in the model.
   float GetLanguageFrequency(const std::string& language_code) const;
 
   // Informs the model that a page with the given language has been visited.
   void OnPageVisited(const std::string& language_code);
 
+  // Reflect in the model that history from |begin| to |end| gets cleared.
+  void ClearHistory(base::Time begin, base::Time end);

[groby-ooo-7-16, 2017/01/25 16:12:45]

Huh. I thought we had a TimeRange, but apparently only blink does...

[jkrcal, 2017/01/26 15:46:22]

Acknowledged.

+
  private:
   PrefService* pref_service_;
 
   DISALLOW_COPY_AND_ASSIGN(LanguageModel);
 };
 
 }  // namespace translate
 
 #endif  // COMPONENTS_TRANSLATE_CORE_BROWSER_LANGUAGE_MODEL_H_