Remove the last usages of PrefObserver outside of Prefs.

chrome/browser/tab_contents/spellchecker_submenu_observer_hunspell.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/tab_contents/spellchecker_submenu_observer.h"
 
 #include "base/logging.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/api/prefs/pref_member.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 135 matching lines @@
 
   // Check to see if one of the spell check language ids have been clicked.
   Profile* profile = proxy_->GetProfile();
   DCHECK(profile);
   if (command_id >= IDC_SPELLCHECK_LANGUAGES_FIRST &&
       command_id < IDC_SPELLCHECK_LANGUAGES_LAST) {
     const size_t language = command_id - IDC_SPELLCHECK_LANGUAGES_FIRST;
     if (profile && language < languages_.size()) {
       StringPrefMember dictionary_language;
       dictionary_language.Init(prefs::kSpellCheckDictionary,
-                               profile->GetPrefs(),
-                               NULL);
+                               profile->GetPrefs());
       dictionary_language.SetValue(languages_[language]);
     }
     return;
   }
 
   content::RenderViewHost* rvh = proxy_->GetRenderViewHost();
   switch (command_id) {
     case IDC_CHECK_SPELLING_WHILE_TYPING:
       profile->GetPrefs()->SetBoolean(
           prefs::kEnableSpellCheck,
           !profile->GetPrefs()->GetBoolean(prefs::kEnableSpellCheck));
       if (rvh)
         rvh->Send(new SpellCheckMsg_ToggleSpellCheck(rvh->GetRoutingID()));
       break;
   }
 }