Cleanup: Pull some browser keep alive functions into its own file.

chrome/browser/lifetime/application_lifetime_aura.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 "ash/shell.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
+#include "chrome/browser/lifetime/browser_keep_alive.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
 #include "chrome/common/chrome_switches.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/views/widget/widget.h"
 
 namespace chrome {
 
 void HandleAppExitingForPlatform() {
   // Close all non browser windows now. Those includes notifications
   // and windows created by Ash (launcher, background, etc).
   g_browser_process->notification_ui_manager()->CancelAll();
 
   // This may be called before |ash::Shell| is initialized when
   // XIOError is reported.  crbug.com/150633.
   if (ash::Shell::HasInstance()) {
     // Releasing the capture will close any menus that might be open:
     // http://crbug.com/134472
     aura::client::GetCaptureClient(ash::Shell::GetPrimaryRootWindow())->
         SetCapture(NULL);
   }
 
   views::Widget::CloseAllSecondaryWidgets();
 
 #if defined(OS_CHROMEOS)
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableZeroBrowsersOpenForTests)) {
     // App is exiting, call DecrementKeepAliveCount() on behalf of Aura Shell.
-    DecrementKeepAliveCount();
+    browser_lifetime::DecrementKeepAliveCount();
     // Make sure we have notified the session manager that we are exiting.
     // This might be called from FastShutdown() or CloseAllBrowsers(), but not
     // if something prevents a browser from closing before SetTryingToQuit()
     // gets called (e.g. browser->TabsNeedBeforeUnloadFired() is true).
     // NotifyAndTerminate does nothing if called more than once.
     NotifyAndTerminate(true);
   }
 #endif  // OS_CHROMEOS
 }
 
 }  // namespace chrome