Fixes possible crashes for ProfileNotification is not found.

chrome/browser/notifications/message_center_notification_manager.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/notifications/message_center_notification_manager.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 146 matching lines @@
   return false;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // MessageCenter::Delegate
 
 void MessageCenterNotificationManager::DisableExtension(
     const std::string& notification_id) {
   ProfileNotification* profile_notification =
       FindProfileNotification(notification_id);
+  if (!profile_notification)
+    return;
+
   std::string extension_id = profile_notification->GetExtensionId();
   DCHECK(!extension_id.empty());  // or UI should not have enabled the command.
   DesktopNotificationService* service =
       DesktopNotificationServiceFactory::GetForProfile(
           profile_notification->profile());
   service->SetExtensionEnabled(extension_id, false);
 }
 
 void MessageCenterNotificationManager::DisableNotificationsFromSource(
     const std::string& notification_id) {
   ProfileNotification* profile_notification =
       FindProfileNotification(notification_id);
+  if (!profile_notification)
+    return;
+
   // UI should not have enabled the command if there is no valid source.
   DCHECK(profile_notification->notification().origin_url().is_valid());
   DesktopNotificationService* service =
       DesktopNotificationServiceFactory::GetForProfile(
           profile_notification->profile());
   service->DenyPermission(profile_notification->notification().origin_url());
 }
 
 void MessageCenterNotificationManager::ShowSettings(
     const std::string& notification_id) {
   // The per-message-center Settings button passes an empty string.
   if (notification_id.empty()) {
     NOTIMPLEMENTED();
     return;
   }
 
   ProfileNotification* profile_notification =
       FindProfileNotification(notification_id);
+  if (!profile_notification)
+    return;
+
   Browser* browser =
       chrome::FindOrCreateTabbedBrowser(profile_notification->profile(),
                                         chrome::HOST_DESKTOP_TYPE_NATIVE);
   if (profile_notification->GetExtensionId().empty())
     chrome::ShowContentSettings(browser, CONTENT_SETTINGS_TYPE_NOTIFICATIONS);
   else
     chrome::ShowExtensions(browser, std::string());
 }
 
 void MessageCenterNotificationManager::ShowSettingsDialog(
@@ skipping 10 matching lines @@
   // directly to MessageCenter, but this method will be called for the removals
   // of such notifications.
   NotificationMap::const_iterator iter =
       profile_notifications_.find(notification_id);
   if (iter != profile_notifications_.end())
     RemoveProfileNotification(iter->second, by_user);
 }
 
 void MessageCenterNotificationManager::OnNotificationClicked(
     const std::string& notification_id) {
-  FindProfileNotification(notification_id)->notification().Click();
+  ProfileNotification* profile_notification =
+      FindProfileNotification(notification_id);
+  if (!profile_notification)
+    return;
+  profile_notification->notification().Click();
 }
 void MessageCenterNotificationManager::OnNotificationButtonClicked(
     const std::string& notification_id,
     int button_index) {
-  FindProfileNotification(notification_id)->notification().ButtonClick(
-      button_index);
+  ProfileNotification* profile_notification =
+      FindProfileNotification(notification_id);
+  if (!profile_notification)
+    return;
+  profile_notification->notification().ButtonClick(button_index);
 }
 
 
 ////////////////////////////////////////////////////////////////////////////////
 // ImageDownloads
 
 MessageCenterNotificationManager::ImageDownloads::ImageDownloads(
     message_center::MessageCenter* message_center)
     : message_center_(message_center) {
 }
@@ skipping 158 matching lines @@
   profile_notification->notification().Close(by_user);
   std::string id = profile_notification->notification().notification_id();
   profile_notifications_.erase(id);
   delete profile_notification;
 }
 
 MessageCenterNotificationManager::ProfileNotification*
     MessageCenterNotificationManager::FindProfileNotification(
         const std::string& id) const {
   NotificationMap::const_iterator iter = profile_notifications_.find(id);
-  // If the notification is shown in UI, it must be in the map.
-  DCHECK(iter != profile_notifications_.end());
-  DCHECK((*iter).second);
+  if (iter == profile_notifications_.end() || !(*iter).second)

[Dmitry Titov, 2013/04/17 21:58:52]

I think we don't need the second part of the check. At this point the
notification is most likely simply removed. In fact, I'd remove the LOG as well
(it's expected condition, sorta), so the whoel this if() can go.

[Jun Mukai, 2013/04/18 03:08:10]

removed. thanks!

+    LOG(ERROR) << "Missing ProfileNotification for " << id;
+
+  if (iter == profile_notifications_.end())
+    return NULL;
+
   return (*iter).second;
 }