Remove stl_util's STLDeleteContainerPairSecondPointers from prefs.

components/prefs/pref_notifier_impl.h

 // Copyright (c) 2011 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_PREFS_PREF_NOTIFIER_IMPL_H_
 #define COMPONENTS_PREFS_PREF_NOTIFIER_IMPL_H_
 
 #include <list>
+#include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
 #include "components/prefs/base_prefs_export.h"
 #include "components/prefs/pref_notifier.h"
@@ skipping 23 matching lines @@
 
  protected:
   // PrefNotifier overrides.
   void OnPreferenceChanged(const std::string& pref_name) override;
   void OnInitializationCompleted(bool succeeded) override;
 
   // A map from pref names to a list of observers. Observers get fired in the
   // order they are added. These should only be accessed externally for unit
   // testing.
   typedef base::ObserverList<PrefObserver> PrefObserverList;
-  typedef base::hash_map<std::string, PrefObserverList*> PrefObserverMap;
+  typedef base::hash_map<std::string, std::unique_ptr<PrefObserverList>>
+      PrefObserverMap;
 
   typedef std::list<base::Callback<void(bool)>> PrefInitObserverList;
 
   const PrefObserverMap* pref_observers() const { return &pref_observers_; }
 
  private:
   // For the given pref_name, fire any observer of the pref. Virtual so it can
   // be mocked for unit testing.
   virtual void FireObservers(const std::string& path);
 
   // Weak reference; the notifier is owned by the PrefService.
   PrefService* pref_service_;
 
   PrefObserverMap pref_observers_;
   PrefInitObserverList init_observers_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefNotifierImpl);
 };
 
 #endif  // COMPONENTS_PREFS_PREF_NOTIFIER_IMPL_H_