In WinAura, also kill the Metro viewer process in AttemptExit().

chrome/browser/metro_viewer/metro_viewer_process_host_win.cc

 // Copyright 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.
 
 #include "chrome/browser/metro_viewer/metro_viewer_process_host_win.h"
 
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part_aurawin.h"
 #include "chrome/browser/ui/ash/ash_init.h"
@@ skipping 39 matching lines @@
       ipc_channel_name.c_str(),
       IPC::Channel::MODE_NAMED_SERVER,
       this,
       content::BrowserThread::GetMessageLoopProxyForThread(
           content::BrowserThread::IO)));
 }
 
 MetroViewerProcessHost::~MetroViewerProcessHost() {
 }
 
+base::ProcessId MetroViewerProcessHost::GetViewerProcessId() {
+  if (channel_)
+    return channel_->peer_pid();
+  return base::kNullProcessId;
+}
+
 bool MetroViewerProcessHost::Send(IPC::Message* msg) {
   return channel_->Send(msg);
 }
 
 bool MetroViewerProcessHost::OnMessageReceived(const IPC::Message& message) {
   DCHECK(CalledOnValidThread());
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(MetroViewerProcessHost, message)
     IPC_MESSAGE_HANDLER(MetroViewerHostMsg_SetTargetSurface, OnSetTargetSurface)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ skipping 29 matching lines @@
   scoped_refptr<AcceleratedPresenter> any_window =
       AcceleratedPresenter::GetForWindow(NULL);
   any_window->SetNewTargetWindow(hwnd);
   aura::RemoteRootWindowHostWin::Instance()->Connected(this);
   // Tell the rest of Chrome that Ash is running.
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_ASH_SESSION_STARTED,
       content::NotificationService::AllSources(),
       content::NotificationService::NoDetails());
 }