cros: Remove the unneed default ctor from ScreenLockLibrary interface.

chrome/browser/chromeos/cros/screen_lock_library.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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 CHROME_BROWSER_CHROMEOS_CROS_SCREEN_LOCK_LIBRARY_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_SCREEN_LOCK_LIBRARY_H_
 #pragma once
 
-#include "base/observer_list.h"
-#include "third_party/cros/chromeos_screen_lock.h"
-
 namespace chromeos {
 
-// This interface defines interaction with the ChromeOS screen lock
-// APIs.
+// This interface handles the interaction with the ChromeOS screen lock API.
 class ScreenLockLibrary {
  public:
   class Observer {
    public:
     virtual ~Observer() {}
+
     virtual void LockScreen(ScreenLockLibrary* obj) = 0;
     virtual void UnlockScreen(ScreenLockLibrary* obj) = 0;
     virtual void UnlockScreenFailed(ScreenLockLibrary* obj) = 0;
   };
-  ScreenLockLibrary() {}
+
   virtual ~ScreenLockLibrary() {}
+
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
 
   // Notifies PowerManager that screen lock has been completed.
   virtual void NotifyScreenLockCompleted() = 0;
+
   // Notifies PowerManager that a user requested to lock the screen.
   virtual void NotifyScreenLockRequested() = 0;
+
   // Notifies PowerManager that a user unlocked the screen.
   virtual void NotifyScreenUnlockRequested() = 0;
+
   // Notifies PowerManager that screen is unlocked.
   virtual void NotifyScreenUnlockCompleted() = 0;
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via CrosLibrary::Get().
   static ScreenLockLibrary* GetImpl(bool stub);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_SCREEN_LOCK_LIBRARY_H_