Fix panels being removed from PanelManager prematurely.

chrome/common/chrome_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 CHROME_COMMON_CHROME_NOTIFICATION_TYPES_H_
 #define CHROME_COMMON_CHROME_NOTIFICATION_TYPES_H_
 #pragma once
 
 #include "content/public/browser/notification_types.h"
 
@@ skipping 924 matching lines @@
   // Sent when panel gains/loses focus.
   // The source is the Panel, no details.
   // Used only in unit testing.
   NOTIFICATION_PANEL_CHANGED_ACTIVE_STATUS,
 
   // Sent when panel is minimized/restored/shows title only etc.
   // The source is the Panel, no details.
   // Used only in unit testing.
   NOTIFICATION_PANEL_CHANGED_EXPANSION_STATE,
 
+  // Sent from the destructor of Panel class.
+  // Source is the panel being deleted. No details.
+  // Used only in unit testing.
+  NOTIFICATION_PANEL_DELETED,
+
   // Sent when panel window size is known. This is for platforms where the
   // window creation is async and size of the window only becomes known later.
   // Used only in unit testing.
   NOTIFICATION_PANEL_WINDOW_SIZE_KNOWN,
 
   // Sent when panel's bounds get changed.
   // The source is the Panel, no details.
   // Used only in coordination with notification balloons.
   NOTIFICATION_PANEL_CHANGED_BOUNDS,
 
@@ skipping 17 matching lines @@
   // Currently only Content and Chrome define and use notifications.
   // Custom notifications not belonging to Content and Chrome should start
   // from here.
   NOTIFICATION_CHROME_END,
 };
 
 }  // namespace chrome
 
 
 #endif  // CHROME_COMMON_CHROME_NOTIFICATION_TYPES_H_