browser: Start moving application_lifetime.h functions into chrome namespace.

chrome/browser/lifetime/application_lifetime_mac.mm

 // 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.
 
 // This file contains the penultimate pieces of the Mac shutdown puzzle. For
 // an in-depth overview of the Mac shutdown path, see the comment above
 // -[BrowserCrApplication terminate:].
 
 #include "chrome/browser/lifetime/application_lifetime.h"
 
 #include "base/logging.h"
 #include "chrome/browser/browser_shutdown.h"
 #import "chrome/browser/chrome_browser_application_mac.h"
 
-namespace browser {
+namespace chrome {
 
 // At this point, the user is trying to quit (or the system is forcing the
 // application to quit) and all browsers have been successfully closed. The
 // final step in shutdown is to post the NSApplicationWillTerminateNotification
 // to end the -[NSApplication run] event loop.
 void HandleAppExitingForPlatform() {
   static bool kill_me_now = false;
   CHECK(!kill_me_now);
   kill_me_now = true;
 
   [[NSNotificationCenter defaultCenter]
       postNotificationName:NSApplicationWillTerminateNotification
                     object:NSApp];
 }
 
-}  // namespace browser
+}  // namespace chrome