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

chrome/browser/signin/screenlock_bridge.h

 // Copyright 2014 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 CHROME_BROWSER_SIGNIN_SCREENLOCK_BRIDGE_H_
 #define CHROME_BROWSER_SIGNIN_SCREENLOCK_BRIDGE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 122 matching lines @@
     // Attempts to login the user using an easy unlock key.
     virtual void AttemptEasySignin(const std::string& user_email,
                                    const std::string& secret,
                                    const std::string& key_label) = 0;
 
    protected:
     virtual ~LockHandler() {}
   };
 
   static ScreenlockBridge* Get();
-  static std::string GetAuthenticatedUserEmail(Profile* profile);
+  static std::string GetAuthenticatedUserEmail(const Profile* profile);
 
   void SetLockHandler(LockHandler* lock_handler);
   void SetFocusedUser(const std::string& user_id);
 
   bool IsLocked() const;
   void Lock(Profile* profile);
   void Unlock(Profile* profile);
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
@@ skipping 11 matching lines @@
 
   LockHandler* lock_handler_;  // Not owned
   // The last focused user's id.
   std::string focused_user_id_;
   ObserverList<Observer, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenlockBridge);
 };
 
 #endif  // CHROME_BROWSER_SIGNIN_SCREENLOCK_BRIDGE_H_