Move assorted function in application_lifetime to where they are used.

chrome/browser/browser_shutdown.h

 // 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.
 
-#ifndef CHROME_BROWSER_BROWSER_SHUTDOWN_H__
-#define CHROME_BROWSER_BROWSER_SHUTDOWN_H__
+#ifndef CHROME_BROWSER_BROWSER_SHUTDOWN_H_
+#define CHROME_BROWSER_BROWSER_SHUTDOWN_H_
 
 class PrefRegistrySimple;
 
 namespace browser_shutdown {
 
 enum ShutdownType {
   // an uninitialized value
   NOT_VALID = 0,
   // the last browser window was closed
   WINDOW_CLOSE,
@@ skipping 44 matching lines @@
 // except from appropriate places in BrowserList. To quit, use usual means,
 // e.g., using |chrome_browser_application_mac::Terminate()| on the Mac, or
 // |BrowserList::CloseAllWindowsAndExit()| on other platforms. To stop quitting,
 // use |chrome_browser_application_mac::CancelTerminate()| on the Mac; other
 // platforms can call SetTryingToQuit(false) directly.
 void SetTryingToQuit(bool quitting);
 
 // General accessor.
 bool IsTryingToQuit();
 
+// Starts to collect shutdown traces. On ChromeOS this will start immediately
+// on AttemptUserExit() and all other systems will start once all tabs are
+// closed.
+void StartShutdownTracing();
+
 }  // namespace browser_shutdown
 
-#endif  // CHROME_BROWSER_BROWSER_SHUTDOWN_H__
+#endif  // CHROME_BROWSER_BROWSER_SHUTDOWN_H_