Bug 137640 [CommonNavigator] New java elements not selected in project explorer
3.2 RC1 - show the Project Explorer view - create a Java project - select the project and create a package (e.g. using the toolbar button) - the package is created, but not selected (it does get selected in the Package Explorer) - select the package - create a new class - the class is created, but not selected (works in the PE) In both cases, the selection gets cleared. This results in subsequent package or class creations not knowing which source folder they should apply to. E.g. try creating two packages in a row.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
*/
	public final NavigatorContentExtension getExtension(
			INavigatorContentDescriptor aDescriptorKey) {
		return getExtension(aDescriptorKey, true);
	}
	/**
	 * 
	 * @param aDescriptorKey
	 * @param toLoadIfNecessary
	 *            True if the extension should be loaded if it is not already.
	 * @return The instance of the extension for the given descriptor key.
	 */
	public final NavigatorContentExtension getExtension(
			INavigatorContentDescriptor aDescriptorKey,
			boolean toLoadIfNecessary) {
		
		NavigatorContentExtension extension = (NavigatorContentExtension) contentExtensions
				.get(aDescriptorKey);
		if (extension != null || !toLoadIfNecessary) {
			return extension;
		}
		/*
		 * If the descriptor instance hasn't been created yet, then we need to
		 * (1) verify that it wasn't added by another thread, (2) create and add
		 * the result into the map
		 */
		synchronized (this) {
			extension = (NavigatorContentExtension) contentExtensions
					.get(aDescriptorKey);
			if (extension == null) {