[Cleanup] Const-correct the profile() method for the EasyUnlockService

chrome/browser/profiles/profile.h

 // Copyright (c) 2012 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.
 
 // This class gathers state related to a single user profile.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_H_
 
 #include <string>
@@ skipping 174 matching lines @@
   // Returns whether the profile is a legacy supervised user profile.
   virtual bool IsLegacySupervised() = 0;
 
   // Accessor. The instance is created upon first access.
   virtual ExtensionSpecialStoragePolicy*
       GetExtensionSpecialStoragePolicy() = 0;
 
   // Retrieves a pointer to the PrefService that manages the
   // preferences for this user profile.
   virtual PrefService* GetPrefs() = 0;
+  virtual const PrefService* GetPrefs() const = 0;
 
   // Retrieves a pointer to the PrefService that manages the default zoom
   // level and the per-host zoom levels for this user profile.
   // TODO(wjmaclean): Remove this when HostZoomMap migrates to StoragePartition.
   virtual chrome::ChromeZoomLevelPrefs* GetZoomLevelPrefs();
 
   // Retrieves a pointer to the PrefService that manages the preferences
   // for OffTheRecord Profiles.  This PrefService is lazily created the first
   // time that this method is called.
   virtual PrefService* GetOffTheRecordPrefs() = 0;
@@ skipping 195 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(Profile);
 };
 
 // The comparator for profile pointers as key in a map.
 struct ProfileCompare {
   bool operator()(Profile* a, Profile* b) const;
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_H_