Mac: reform our shutdown routine.

chrome/browser/app_controller_mac.h

Index: chrome/browser/app_controller_mac.h
diff --git a/chrome/browser/app_controller_mac.h b/chrome/browser/app_controller_mac.h
index 11f705fcdcfa80ebc790559735fa9e5134107681..86cf2d9156a6282d2268fb03f229f8c25af1016d 100644
--- a/chrome/browser/app_controller_mac.h
+++ b/chrome/browser/app_controller_mac.h
@@ -56,6 +56,13 @@ class Profile;
 - (void)didEndMainMessageLoop;
 - (Profile*)defaultProfile;
 
+// Try to close all browser windows, and if that succeeds then quit.
+- (BOOL)tryToTerminateApplication:(NSApplication*)app;
+
+// Stop trying to terminate the application. That is, prevent the final browser
+// window closure from causing the application to quit.
+- (void)stopTryingToTerminateApplication:(NSApplication*)app;
+
 // Show the preferences window, or bring it to the front if it's already
 // visible.
 - (IBAction)showPreferences:(id)sender;