Display "Restart to update" dialog to Chrome OS users.

chrome/browser/lifetime/application_lifetime.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_LIFETIME_APPLICATION_LIFETIME_H_
 #define CHROME_BROWSER_LIFETIME_APPLICATION_LIFETIME_H_
 
 #include "base/compiler_specific.h"
 #include "build/build_config.h"
 
@@ skipping 58 matching lines @@
 void SessionEnding();
 
 #endif  // !defined(OS_ANDROID)
 
 // Emits APP_TERMINATING notification. It is guaranteed that the
 // notification is sent only once.
 void NotifyAppTerminating();
 
 // Send out notifications.
 // For ChromeOS, also request session manager to end the session.
-void NotifyAndTerminate(bool fast_path);
+// |always_reboot| is used on ChromeOS to signal that a reboot is required, even
+// if a system update is not available. This is useful if, for example, a
+// component flash update was applied.

[Nico, 2016/12/02 01:20:07]

Consider using enums instead of bools. Writing

  enum RebootStyle { kForceReboot, kNoReboot };
  void NotifyAndTerminate(bool fast_path, bool always_reboot = kNoReboot);

is not any more work, but at the calling side

  foo->NotifyAndTerminal(foo, ApplicationLifetime::kForceReboot);

is way more readable. (Also, style guide discourages default args iirc)

[Greg K, 2016/12/03 00:05:42]

I agree about the enumeration. That being said, I read the style guide and it
does encourage using a default argument or function overload for a case like
this were only one caller cares about that value.

That being said, it says when in doubt, prefer function overloads so that's how
I will do this.

+void NotifyAndTerminate(bool fast_path, bool always_reboot = false);
 
 #if !defined(OS_ANDROID)
 // Called once the application is exiting.
 void OnAppExiting();
 
 // Called once the application is exiting to do any platform specific
 // processing required.
 void HandleAppExitingForPlatform();
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_LIFETIME_APPLICATION_LIFETIME_H_