Remove the last usages of PrefObserver outside of Prefs.

chrome/browser/chromeos/input_method/browser_state_monitor_unittest.cc

 // 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.
 
 #include "chrome/browser/chromeos/input_method/browser_state_monitor.h"
 
 #include "chrome/browser/api/prefs/pref_member.h"
 #include "chrome/browser/chromeos/input_method/mock_input_method_manager.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
@@ skipping 297 matching lines @@
 }
 
 TEST(BrowserStateMonitorTest, TestUpdatePrefOnBrowserScreenDetails) {
   TestingPrefService prefs;
   RegisterTestPrefs(&prefs);
   MockInputMethodManager mock_manager;
   TestableBrowserStateMonitor monitor(&mock_manager);
   monitor.SetPrefServiceForTesting(&prefs);
 
   StringPrefMember previous;
-  previous.Init(prefs::kLanguagePreviousInputMethod, &prefs, NULL);
+  previous.Init(prefs::kLanguagePreviousInputMethod, &prefs);
   EXPECT_EQ("", previous.GetValue());
   StringPrefMember current;
-  current.Init(prefs::kLanguageCurrentInputMethod, &prefs, NULL);
+  current.Init(prefs::kLanguageCurrentInputMethod, &prefs);
   EXPECT_EQ("", current.GetValue());
 
   monitor.Observe(chrome::NOTIFICATION_LOGIN_USER_CHANGED,
                   content::NotificationService::AllSources(),
                   content::NotificationService::NoDetails());
   EXPECT_EQ(InputMethodManager::STATE_BROWSER_SCREEN, monitor.state());
   monitor.Observe(chrome::NOTIFICATION_SESSION_STARTED,
                   content::NotificationService::AllSources(),
                   content::NotificationService::NoDetails());
   EXPECT_EQ(InputMethodManager::STATE_BROWSER_SCREEN, monitor.state());
@@ skipping 35 matching lines @@
   monitor.InputMethodChanged(&mock_manager, false);
   EXPECT_EQ(0, monitor.update_local_state_count());
   EXPECT_EQ(5, monitor.update_user_pref_count());
   EXPECT_EQ(input_method_id_3, monitor.last_user_pref());
   EXPECT_EQ(input_method_id_2, previous.GetValue());
   EXPECT_EQ(input_method_id_3, current.GetValue());
 }
 
 }  // namespace input_method
 }  // namespace chromeos