Bug 126779 [IDE] Removed deprecated project capabilities API and implementation
It was created then deprecated before 2.0 shipped. As has never been API and we don't use it we should delete it.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEWorkbenchPlugin.java
/**
     * Creates an extension.  If the extension plugin has not
     * been loaded a busy cursor will be activated during the duration of
     * the load.
     *
     * @param element the config element defining the extension
     * @param classAttribute the name of the attribute carrying the class
     * @return Object the extension object
     * @throws CoreException
     */
    public static Object createExtension(final IConfigurationElement element,
			final String classAttribute) throws CoreException {
		
		
		Bundle plugin = Platform.getBundle(element.getNamespace());
		if (plugin.getState() == Bundle.ACTIVE) {
			return element.createExecutableExtension(classAttribute);
		} else {
            final Object[] ret = new Object[1];
            final CoreException[] exc = new CoreException[1];
            BusyIndicator.showWhile(null, new Runnable() {
                public void run() {
                    try {
                        ret[0] = element
                                .createExecutableExtension(classAttribute);
                    } catch (CoreException e) {
                        exc[0] = e;
                    }
                }
            });