Introduce per-tab preferences service.

chrome/browser/prefs/pref_notifier_impl.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/prefs/pref_notifier_impl.h"
 
 #include "base/stl_util.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 
+PrefNotifierImpl::PrefNotifierImpl()
+    : pref_service_(NULL) {
+}
+
 PrefNotifierImpl::PrefNotifierImpl(PrefService* service)
     : pref_service_(service) {
 }
 
 PrefNotifierImpl::~PrefNotifierImpl() {
   DCHECK(CalledOnValidThread());
 
   // Verify that there are no pref observers when we shut down.
   for (PrefObserverMap::iterator it = pref_observers_.begin();
        it != pref_observers_.end(); ++it) {
@@ skipping 74 matching lines @@
     return;
 
   NotificationObserverList::Iterator it(*(observer_iterator->second));
   content::NotificationObserver* observer;
   while ((observer = it.GetNext()) != NULL) {
     observer->Observe(chrome::NOTIFICATION_PREF_CHANGED,
                       content::Source<PrefService>(pref_service_),
                       content::Details<const std::string>(&path));
   }
 }
+
+void PrefNotifierImpl::SetPrefService(PrefService* pref_service) {
+  DCHECK(pref_service_ == NULL);
+  pref_service_ = pref_service;
+}