Posted at the start of the updateWindows method to indicate that the application is about to update its windows.
The notification object is sharedApplication. This notification does not contain a userInfo dictionary.
Available in Mac OS X v10.0 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)