Bug 161738 [Undo] - API - promote ability to quietly compute status to operations API
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/undo/WorkspaceUndoMonitor.java
* Get a change listener for listening to resource changes.
	 * 
	 * @return the resource change listeners
	 */
	private IResourceChangeListener getResourceChangeListener() {
		return new IResourceChangeListener() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.core.resources.IResourceChangeListener#resourceChanged(org.eclipse.core.resources.IResourceChangeEvent)
			 */
			public void resourceChanged(IResourceChangeEvent event) {
				
				
				if (operationInProgress != null) {
					return;
				}
				if (event.getType() == IResourceChangeEvent.POST_CHANGE
						|| event.getType() == IResourceChangeEvent.POST_BUILD) {
					
					
					incrementChangeCount();
					if (numChanges >= CHANGE_THRESHHOLD) {
						checkOperationHistory();
					}
				}
			}
		};
	}
	/**