Some fixups for app notifications:

chrome/browser/extensions/app_notification_manager.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/extensions/app_notification_manager.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/file_path.h"
 #include "base/location.h"
@@ skipping 92 matching lines @@
 
   SyncAddChange(*linked_item);
 
   if (storage_.get()) {
     BrowserThread::PostTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&AppNotificationManager::SaveOnFileThread,
             this, extension_id, CopyAppNotificationList(list)));
   }
+
+  content::NotificationService::current()->Notify(
+      chrome::NOTIFICATION_APP_NOTIFICATION_STATE_CHANGED,
+      content::Source<Profile>(profile_),
+      content::Details<const std::string>(&extension_id));
+
   return true;
 }
 
 const AppNotificationList* AppNotificationManager::GetAll(
     const std::string& extension_id) const {
   if (!loaded())
     return NULL;
   if (ContainsKey(*notifications_, extension_id))
     return &((*notifications_)[extension_id]);
   return NULL;
@@ skipping 11 matching lines @@
 }
 
 const AppNotification* AppNotificationManager::GetLast(
     const std::string& extension_id) {
   if (!loaded())
     return NULL;
   NotificationMap::iterator found = notifications_->find(extension_id);
   if (found == notifications_->end())
     return NULL;
   const AppNotificationList& list = found->second;
+  if (list.empty())
+    return NULL;
   return list.rbegin()->get();
 }
 
 void AppNotificationManager::ClearAll(const std::string& extension_id) {
   if (!loaded())
     return;
   NotificationMap::iterator found = notifications_->find(extension_id);
   if (found != notifications_->end()) {
     SyncClearAllChange(found->second);
     notifications_->erase(found);
   }
 
   if (storage_.get()) {
     BrowserThread::PostTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&AppNotificationManager::DeleteOnFileThread,
             this, extension_id));
   }
+
+  content::NotificationService::current()->Notify(
+      chrome::NOTIFICATION_APP_NOTIFICATION_STATE_CHANGED,
+      content::Source<Profile>(profile_),
+      content::Details<const std::string>(&extension_id));
 }
 
 void AppNotificationManager::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   CHECK(type == chrome::NOTIFICATION_EXTENSION_UNINSTALLED);
   ClearAll(*content::Details<const std::string>(details).ptr());
 }
 
@@ skipping 259 matching lines @@
   AppNotificationList& list = GetAllInternal(extension_id);
   RemoveByGuid(&list, guid);
 
   if (storage_.get()) {
     BrowserThread::PostTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&AppNotificationManager::SaveOnFileThread,
             this, extension_id, CopyAppNotificationList(list)));
   }
+
+  content::NotificationService::current()->Notify(
+      chrome::NOTIFICATION_APP_NOTIFICATION_STATE_CHANGED,
+      content::Source<Profile>(profile_),
+      content::Details<const std::string>(&extension_id));
 }
 
 // static
 SyncData AppNotificationManager::CreateSyncDataFromNotification(
     const AppNotification& notification) {
   DCHECK(!notification.is_local());
   sync_pb::EntitySpecifics specifics;
   sync_pb::AppNotificationSpecifics* notif_specifics =
       specifics.MutableExtension(sync_pb::app_notification);
   notif_specifics->set_app_id(notification.extension_id());
@@ skipping 21 matching lines @@
 
   AppNotification* notification = new AppNotification(
       false, specifics.guid(), specifics.app_id(),
       specifics.title(), specifics.body_text());
   if (specifics.has_link_text())
     notification->set_link_text(specifics.link_text());
   if (specifics.has_link_url())
     notification->set_link_url(GURL(specifics.link_url()));
   return notification;
 }