Avoid exiting the renderer process if it has a pending render view.

content/common/notification_type.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_COMMON_NOTIFICATION_TYPE_H_
 #define CONTENT_COMMON_NOTIFICATION_TYPE_H_
 #pragma once
 
 // This file describes various types used to describe and filter notifications
 // that pass through the NotificationService.
@@ skipping 390 matching lines @@
 
     // Indicates that a RenderProcessHost was created and its handle is now
     // available. The source will be the RenderProcessHost that corresponds to
     // the process.
     RENDERER_PROCESS_CREATED,
 
     // Indicates that a RenderProcessHost is destructing. The source will be the
     // RenderProcessHost that corresponds to the process.
     RENDERER_PROCESS_TERMINATED,
 
+    // Indicates that a render process is starting to exit, such that it should
+    // not be used for future navigations.  The source will be the
+    // RenderProcessHost that corresponds to the process.
+    RENDERER_PROCESS_CLOSING,
+
     // Indicates that a render process was closed (meaning it exited, but the
     // RenderProcessHost might be reused).  The source will be the corresponding
     // RenderProcessHost.  The details will be a RendererClosedDetails struct.
     // This may get sent along with RENDERER_PROCESS_TERMINATED.
     RENDERER_PROCESS_CLOSED,
 
     // Indicates that a render process has become unresponsive for a period of
     // time. The source will be the RenderWidgetHost that corresponds to the
     // hung view, and no details are expected.
     RENDERER_PROCESS_HANG,
@@ skipping 885 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  // CONTENT_COMMON_NOTIFICATION_TYPE_H_