Bug 215244 [Markers] Show All menu entry is not persisted
If you select Show All it will not be restored on return. Not an issue in the dialog.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
* @return MarkerComparator
	 */
	MarkerComparator getComparator() {
		if (comparator == null) {
			MarkerField field = null;
			if (getCategoryGroup() != null)
				field = getCategoryGroup().getMarkerField();
			comparator = new MarkerComparator(field, generator.getAllFields());
			comparator.restore(this.memento);
		}
		return comparator;
	}
	/**
	 * Return the elements in the adapter.
	 * 
	 * @return Object[]
	 */
	MarkerItem[] getElements() {
		if (refreshingMarkers()) {
			return MarkerSupportInternalUtilities.EMPTY_MARKER_ITEM_ARRAY;
		}
		if (isShowingHierarchy() && categories != null) {
			return categories;
		}
		return currentMap.toArray();
	}
	/**
	 * Return the currently enabled filters.
	 * 
	 * @return Collection of MarkerFieldFilterGroup