Bug 96947 Bad progress reporting on rename method
org.eclipse.ltk.core.refactoring/src/org/eclipse/ltk/core/refactoring/PerformChangeOperation.java
* @param undoName the name used to present the undo change on the undo
	 *  stack. Must be a human-readable string. Must not be <code>null</code>
	 *  if manager is unequal <code>null</code>
	 */
	public void setUndoManager(IUndoManager manager, String undoName) {
		if (manager != null) {
			Assert.isNotNull(undoName);
		}
		fUndoManager= manager;
		fUndoName= undoName;
	}
	/**
	 * {@inheritDoc}
	 */
	public void run(IProgressMonitor pm) throws CoreException {
		if (pm == null)
			pm= new NullProgressMonitor();
		try {
			fChangeExecuted= false;
			if (createChange()) {
				pm.beginTask("", 2); 
				pm.subTask(""); 
				fCreateChangeOperation.run(new SubProgressMonitor(pm, 1));
				fChange= fCreateChangeOperation.getChange();
				if (fChange != null) {
					executeChange(new SubProgressMonitor(pm, 1));
				} else {
					pm.worked(1);
				}
			} else {