Adds some debugging code in hopes of identifying a crasher.

content/public/browser/notification_types.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_NOTIFICATION_TYPES_H_
 #define CONTENT_PUBLIC_BROWSER_NOTIFICATION_TYPES_H_
 #pragma once
 
 // This file describes various types used to describe and filter notifications
 // that pass through the NotificationService.
@@ skipping 247 matching lines @@
   // This notification is sent when a TabContents is being hidden, e.g. due
   // to switching away from this tab.  The source is a Source<TabContents>.
   NOTIFICATION_TAB_CONTENTS_HIDDEN,
 
   // This notification is sent when a TabContents is being destroyed. Any
   // object holding a reference to a TabContents can listen to that
   // notification to properly reset the reference. The source is a
   // Source<TabContents>.
   NOTIFICATION_TAB_CONTENTS_DESTROYED,
 
+  // This notification is sent when a TabContentsDelegate is being
+  // destroyed. The source is a Source<TabContentsDelegate>.
+  // TODO(sky): Remove when we figure out http://crbug.com/107172.
+  NOTIFICATION_TAB_CONTENTS_DELEGATE_DESTROYED,
+
   // A RenderViewHost was created for a TabContents. The source is the
   // associated TabContents, and the details is the RenderViewHost
   // pointer.
   NOTIFICATION_RENDER_VIEW_HOST_CREATED_FOR_TAB,
 
   // Notification than an interstitial has become associated with a tab. The
   // source is the TabContents, the details not used.
   NOTIFICATION_INTERSTITIAL_ATTACHED,
 
   // Indicates that a RenderProcessHost was created and its handle is now
@@ skipping 144 matching lines @@
   // of a temporary zoom level change, the details is an empty string.
   NOTIFICATION_ZOOM_LEVEL_CHANGED,
 
   // Custom notifications used by the embedder should start from here.
   NOTIFICATION_CONTENT_END,
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_NOTIFICATION_TYPES_H_