Use stub impl when libcros fails to load

chrome/browser/chromeos/cros/screen_lock_library.cc

 // 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.
 
 #include "chrome/browser/chromeos/cros/screen_lock_library.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 10 matching lines @@
 
   virtual ~ScreenLockLibraryImpl() {
     if (screen_lock_connection_) {
       chromeos::DisconnectScreenLock(screen_lock_connection_);
       screen_lock_connection_ = NULL;
     }
   }
 
   // Begin ScreenLockLibrary implementation.
   virtual void Init() OVERRIDE {
-    if (CrosLibrary::Get()->EnsureLoaded()) {
-      screen_lock_connection_ =
-          chromeos::MonitorScreenLock(&ScreenLockedHandler, this);
-    }
+    DCHECK(CrosLibrary::Get()->libcros_loaded());
+    screen_lock_connection_ =
+        chromeos::MonitorScreenLock(&ScreenLockedHandler, this);
   }
 
   virtual void AddObserver(Observer* observer) OVERRIDE {
     observers_.AddObserver(observer);
   }
 
   virtual void RemoveObserver(Observer* observer) OVERRIDE {
     observers_.RemoveObserver(observer);
   }
 
@@ skipping 95 matching lines @@
     impl = new ScreenLockLibraryImpl();
   impl->Init();
   return impl;
 }
 
 }  // namespace chromeos
 
 // Allows InvokeLater without adding refcounting. This class is a Singleton and
 // won't be deleted until it's last InvokeLater is run.
 DISABLE_RUNNABLE_METHOD_REFCOUNT(chromeos::ScreenLockLibraryImpl);