Remove two unused prefs keys.

chrome/browser/ui/browser_ui_prefs.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/ui/browser_ui_prefs.h"
 
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 107 matching lines @@
   registry->RegisterBooleanPref(
       prefs::kDevToolsDisabled,
       false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterDictionaryPref(
       prefs::kBrowserWindowPlacement,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterDictionaryPref(
       prefs::kBrowserWindowPlacementPopup,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterDictionaryPref(
-      prefs::kPreferencesWindowPlacement,
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kImportBookmarks,
       true,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kImportHistory,
       true,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kImportHomepage,
@@ skipping 60 matching lines @@
     scoped_refptr<user_prefs::PrefRegistrySyncable> registry(
         static_cast<user_prefs::PrefRegistrySyncable*>(
             prefs->DeprecatedGetPrefRegistry()));
     registry->RegisterDictionaryPref(
         window_pref.c_str(), user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   }
 }
 
 
 }  // namespace chrome