Use PluginPrefs in ChromePluginServiceFilter to check whether a plugin is enabled.

chrome/browser/plugin_data_remover_helper.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/plugin_data_remover_helper.h"
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/plugin_data_remover.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/common/chrome_notification_types.h"
 #include "content/browser/browser_thread.h"
 #include "content/common/notification_service.h"
 
 // The internal class is refcounted so it can outlive PluginDataRemoverHelper.
 class PluginDataRemoverHelper::Internal
     : public base::RefCountedThreadSafe<PluginDataRemoverHelper::Internal> {
  public:
   Internal(const char* pref_name, PrefService* prefs)
       : pref_name_(pref_name), prefs_(prefs) {}
 
@@ skipping 44 matching lines @@
 PluginDataRemoverHelper::~PluginDataRemoverHelper() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (internal_)
     internal_->Invalidate();
 }
 
 void PluginDataRemoverHelper::Init(const char* pref_name,
                                    PrefService* prefs,
                                    NotificationObserver* observer) {
   pref_.Init(pref_name, prefs, observer);
-  registrar_.Add(this, content::NOTIFICATION_PLUGIN_ENABLE_STATUS_CHANGED,
+  registrar_.Add(this, chrome::NOTIFICATION_PLUGIN_ENABLE_STATUS_CHANGED,
                  NotificationService::AllSources());
   internal_ = make_scoped_refptr(new Internal(pref_name, prefs));
   internal_->StartUpdate();
 }
 
 void PluginDataRemoverHelper::Observe(int type,
                                       const NotificationSource& source,
                                       const NotificationDetails& details) {
-  if (type == content::NOTIFICATION_PLUGIN_ENABLE_STATUS_CHANGED) {
+  if (type == chrome::NOTIFICATION_PLUGIN_ENABLE_STATUS_CHANGED) {
     internal_->StartUpdate();
   } else {
     NOTREACHED();
   }
 }