Fix a crash where the ResourceMessageFilter is deleted

chrome/common/notification_type.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef CHROME_COMMON_NOTIFICATION_TYPE_H_
 #define CHROME_COMMON_NOTIFICATION_TYPE_H_
 
 // This file describes various types used to describe and filter notifications
 // that pass through the NotificationService.
 //
@@ skipping 139 matching lines @@
     // this notifiation if you need to keep track of our internal SSL state.
     //
     // The source will be the navigation controller associated with the state
     // change.  There are no details.
     SSL_INTERNAL_STATE_CHANGED,
 
     // Download start and stop notifications. Stop notifications can occur on
     // both normal completion or via a cancel operation.
     DOWNLOAD_START, DOWNLOAD_STOP,
 
+    // Lets resource handlers and other interested observers know when the
+    // message filter is being deleted and can no longer be used.
+    RESOURCE_MESSAGE_FILTER_SHUTDOWN,
+
     // Views -------------------------------------------------------------------
 
     // Notification that a view was removed from a view hierarchy.  The source
     // is the view, the details is the parent view.
     VIEW_REMOVED,
 
     // Browser-window ----------------------------------------------------------
 
     // This message is sent after a window has been opened.  The source is a
     // Source<Browser> with a pointer to the new window.  No details are
@@ skipping 384 matching lines @@
 };
 
 inline bool operator==(NotificationType::Type a, NotificationType b) {
   return a == b.value;
 }
 inline bool operator!=(NotificationType::Type a, NotificationType b) {
   return a != b.value;
 }
 
 #endif  // CHROME_COMMON_NOTIFICATION_TYPE_H_