[NTP Snippets] Remove deprecated prefs

components/ntp_snippets/ntp_snippets_service.h

 // Copyright 2015 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_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 233 matching lines @@
   // use |EnterState| instead.
   void EnterStateEnabled(bool fetch_snippets);
 
   // Disables the service. Do not call directly, use |EnterState| instead.
   void EnterStateDisabled();
 
   // Applies the effects of the transition to the SHUT_DOWN state. Do not call
   // directly, use |EnterState| instead.
   void EnterStateShutdown();
 
-  void ClearDeprecatedPrefs();
-
   State state_;
 
   PrefService* pref_service_;
 
   suggestions::SuggestionsService* suggestions_service_;
 
   // All current suggestions (i.e. not discarded ones).
   NTPSnippet::PtrVector snippets_;
 
   // Suggestions that the user discarded. We keep these around until they expire
@@ skipping 51 matching lines @@
   // If the service might be enabled, DisabledReason::NONE will be provided.
   virtual void NTPSnippetsServiceDisabledReasonChanged(DisabledReason) = 0;
 
  protected:
   virtual ~NTPSnippetsServiceObserver() {}
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_