Move use of ShutdownWatcherHelper after early return

chrome/browser/lifetime/application_lifetime.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.
 
 #include "chrome/browser/lifetime/application_lifetime.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 229 matching lines @@
   AttemptExitInternal(true);
 }
 #endif
 
 #if !defined(OS_ANDROID)
 void SessionEnding() {
   // This is a time-limited shutdown where we need to write as much to
   // disk as we can as soon as we can, and where we must kill the
   // process within a hang timeout to avoid user prompts.
 
-  // Start watching for hang during shutdown, and crash it if takes too long.
-  // We disarm when |shutdown_watcher| object is destroyed, which is when we
-  // exit this function.
-  ShutdownWatcherHelper shutdown_watcher;
-  shutdown_watcher.Arm(base::TimeDelta::FromSeconds(90));
-
   // EndSession is invoked once per frame. Only do something the first time.
   static bool already_ended = false;
   // We may get called in the middle of shutdown, e.g. http://crbug.com/70852
   // In this case, do nothing.
   if (already_ended || !content::NotificationService::current())
     return;
   already_ended = true;
 
+  // ~ShutdownWatcherHelper uses IO (it joins a thread). We'll only trigger that
+  // if Terminate() fails, which leaves us in a weird state, or the OS is going
+  // to kill us soon. Either way we don't care about that here.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+
+  // Start watching for hang during shutdown, and crash it if takes too long.
+  // We disarm when |shutdown_watcher| object is destroyed, which is when we
+  // exit this function.
+  ShutdownWatcherHelper shutdown_watcher;
+  shutdown_watcher.Arm(base::TimeDelta::FromSeconds(90));
+
   browser_shutdown::OnShutdownStarting(browser_shutdown::END_SESSION);
 
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_CLOSE_ALL_BROWSERS_REQUEST,
       content::NotificationService::AllSources(),
       content::NotificationService::NoDetails());
 
   // Write important data first.
   g_browser_process->EndSession();
 
@@ skipping 69 matching lines @@
 void OnAppExiting() {
   static bool notified = false;
   if (notified)
     return;
   notified = true;
   HandleAppExitingForPlatform();
 }
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace chrome