Enable NPAPI if policy has plugin policies.

chrome/browser/plugins/plugin_prefs_factory.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/plugins/plugin_prefs_factory.h"
 
 #include "base/path_service.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/plugins/plugin_prefs.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
@@ skipping 57 matching lines @@
       false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterListPref(prefs::kPluginsPluginsList,
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterListPref(prefs::kPluginsDisabledPlugins,
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterListPref(prefs::kPluginsDisabledPluginsExceptions,
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterListPref(prefs::kPluginsEnabledPlugins,
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterBooleanPref(
+      prefs::kEnableNpapi,
+      false,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 content::BrowserContext* PluginPrefsFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return chrome::GetBrowserContextRedirectedInIncognito(context);
 }
 
 bool PluginPrefsFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }
 
 bool PluginPrefsFactory::ServiceIsCreatedWithBrowserContext() const {
   return true;
 }