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
(ProblemFilter) problemFilters.next(), this));
			}
			
			loadFiltersPreference();
		}
		return filters;
	}
	/**
	 * Return the categories for the receiver.
	 * 
	 * @return MarkerCategory[] or <code>null</code> if there are no
	 *         categories.
	 */
	MarkerCategory[] getCategories() {
		if (building) {
			return null;
		}
		return categories;
	}
	/**
	 * Return the group used to generate categories.
	 * 
	 * @return MarkerGroup or <code>null</code>.
	 */
	MarkerGroup getCategoryGroup() {
		return categoryGroup;
	}
	/**
	 * Return a new instance of the receiver with the field
	 *