Bug 223481 [GlobalActions] regression : Refresh is no longer performed in background
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/RefreshAction.java
protected List getSelectedResources() {
		List resources = super.getSelectedResources();
		if (resources.isEmpty()) {
			resources = new ArrayList();
			resources.add(ResourcesPlugin.getWorkspace().getRoot());
		}
		return resources;
	}
	/**
	 * The <code>RefreshAction</code> implementation of this
	 * <code>SelectionListenerAction</code> method ensures that this action is
	 * enabled if the selection is empty, but is disabled if any of the selected
	 * elements are not resources.
	 */
	protected boolean updateSelection(IStructuredSelection s) {
		return (super.updateSelection(s) || s.isEmpty())
				&& getSelectedNonResources().size() == 0;
	}
	/**
	 * Handle the key release.
	 * 
	 * @param event
	 *            the event
	 */
	public void handleKeyReleased(KeyEvent event) {
		if (event.keyCode == SWT.F5 && event.stateMask == 0) {
			refreshAll();
		}
	}
	/**