In Chrome ASH on Windows 8 make sure that the browser object is closed before destroying it.

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/lifetime/application_lifetime.h"
 #include "chrome/browser/ui/ash/ash_init.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list_impl.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/host_desktop.h"
+#include "chrome/browser/ui/tab_contents/tab_contents.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/browser_thread.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ui/aura/remote_root_window_host_win.h"
 #include "ui/metro_viewer/metro_viewer_messages.h"
 #include "ui/surface/accelerated_surface_win.h"
 
+namespace {
+
+void CloseOpenAshBrowsers() {
+  chrome::BrowserListImpl* browser_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
+  if (browser_list) {
+    for (chrome::BrowserListImpl::const_iterator i = browser_list->begin();
+            i != browser_list->end(); ++i) {
+      Browser* browser = *i;
+      browser->window()->Close();
+      // If the attempt to Close the browser fails due to unload handlers on
+      // the page or in progress downloads, etc, destroy all tabs on the page.
+      while (browser->tab_count())
+        delete browser->tab_strip_model()->GetTabContentsAt(0);
+    }
+  }
+}
+
+}  // namespace
+
+
 MetroViewerProcessHost::MetroViewerProcessHost(
     const std::string& ipc_channel_name) {
   g_browser_process->AddRefModule();
   channel_.reset(new IPC::ChannelProxy(
       ipc_channel_name.c_str(),
       IPC::Channel::MODE_NAMED_SERVER,
       this,
       content::BrowserThread::GetMessageLoopProxyForThread(
           content::BrowserThread::IO)));
 }
@@ skipping 20 matching lines @@
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void  MetroViewerProcessHost::OnChannelError() {
   // TODO(cpu): At some point we only close the browser. Right now this
   // is very convenient for developing.
   DLOG(INFO) << "viewer channel error : Quitting browser";
   g_browser_process->ReleaseModule();
+  CloseOpenAshBrowsers();
   chrome::CloseAsh();
 }
 
 void MetroViewerProcessHost::OnSetTargetSurface(
     gfx::NativeViewId target_surface) {
   DLOG(INFO) << __FUNCTION__ << ", target_surface = " << target_surface;
   HWND hwnd = reinterpret_cast<HWND>(target_surface);
 
   chrome::OpenAsh();
 
@@ skipping 35 matching lines @@
                                     uint32 scan_code,
                                     uint32 flags) {
   aura::RemoteRootWindowHostWin::Instance()->OnChar(
       key_code, repeat_count, scan_code, flags);
 }
 
 void MetroViewerProcessHost::OnVisibilityChanged(bool visible) {
   aura::RemoteRootWindowHostWin::Instance()->OnVisibilityChanged(
       visible);
 }