Reset child_process_launcher after notifying observers

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 1885 matching lines @@
   int exit_code = 0;
   base::TerminationStatus status =
       child_process_launcher_.get() ?
       child_process_launcher_->GetChildTerminationStatus(already_dead,
                                                          &exit_code) :
       base::TERMINATION_STATUS_NORMAL_TERMINATION;
 
   RendererClosedDetails details(GetHandle(), status, exit_code);
   mojo_application_host_->WillDestroySoon();
 
-  child_process_launcher_.reset();

[no sievers, 2014/10/17 19:08:29]

This should already provide the old handle because it is queried above.

Of course the handle is not valid anymore, but with your proposed change you are
changing both NOTIFICATION_RENDERER_PROCESS_CLOSED and RenderProcessExited to
NOTIFICATION_RENDERER_PROCESS_ABOUT_TO_CLOSE/RenderProcessAboutToExit which
might have subtle implications.

   channel_.reset();
 
   within_process_died_observer_ = true;
   NotificationService::current()->Notify(
       NOTIFICATION_RENDERER_PROCESS_CLOSED,
       Source<RenderProcessHost>(this),
       Details<RendererClosedDetails>(&details));
   FOR_EACH_OBSERVER(RenderProcessHostObserver,
                     observers_,
                     RenderProcessExited(this, status, exit_code));
   within_process_died_observer_ = false;
 
+  child_process_launcher_.reset();
   gpu_message_filter_ = NULL;
   message_port_message_filter_ = NULL;
   RemoveUserData(kSessionStorageHolderKey);
 
   IDMap<IPC::Listener>::iterator iter(&listeners_);
   while (!iter.IsAtEnd()) {
     iter.GetCurrentValue()->OnMessageReceived(
         ViewHostMsg_RenderProcessGone(iter.GetCurrentKey(),
                                       static_cast<int>(status),
                                       exit_code));
@@ skipping 305 matching lines @@
 
 void RenderProcessHostImpl::DecrementWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_GT(worker_ref_count_, 0);
   --worker_ref_count_;
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
 }  // namespace content