Bug 161738 [Undo] - API - promote ability to quietly compute status to operations API
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/undo/AbstractWorkspaceOperation.java
* @see IWorkspace#run(IWorkspaceRunnable, ISchedulingRule, int,
	 *      IProgressMonitor)
	 */
	protected ISchedulingRule getUndoSchedulingRule() {
		return getWorkspace().getRoot();
	}
	/**
	 * Return a scheduling rule appropriate for redoing this operation.
	 * 
	 * The default implementation considers the redo scheduling rule the same as
	 * the original execution scheduling rule.
	 * 
	 * @return the scheduling rule to use when redoing this operation, or
	 *         <code>null</code> if there are no scheduling restrictions for
	 *         this operation.
	 * 
	 * @see IWorkspace#run(IWorkspaceRunnable, ISchedulingRule, int,
	 *      IProgressMonitor)
	 */
	protected ISchedulingRule getRedoSchedulingRule() {
		return getExecuteSchedulingRule();
	}
	/**
	 * Set the boolean that determines whether the computation of the receiver's
	 * execution, undo, or redo status may consult the user. The default value
	 * is <code>false</code>. This flag should only be set to
	 * <code>true</code> while some type of background/quiet computation of
	 * validity is being performed, and should be restored to <code>false</code>
	 * when complete.
	 *