Bug 214492 [Markers] Need to be able to add filters to existing markers views
Currently you can only add filters to a new markerContentProvider. We need to able to bind them to existing markerContentProviders as well.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerContentGenerator.java
* Adds all markers in the given set of resources to the given list
	 * 
	 * @param results
	 *            The Collection to add new entries to
	 * @param resources
	 * @param group
	 *            the group to filter on. May be <code>null</code>.
	 * @param depth
	 * @param monitor
	 */
	private void findMarkers(Collection results, IResource[] resources,
			MarkerFieldFilterGroup group, int depth, IProgressMonitor monitor) {
		if (resources == null) {
			return;
		}
		
		
		Collection selectedTypes = getMarkerTypes();
		
		HashSet typesToSearch = new HashSet(selectedTypes.size());
		
		
		HashSet includeAllSubtypes = new HashSet(selectedTypes.size());
		typesToSearch.addAll(selectedTypes);
		Iterator iter = selectedTypes.iterator();
		while (iter.hasNext()) {
			MarkerType type = (MarkerType) iter.next();
			Collection subtypes = Arrays.asList(type.getAllSubTypes());
			if (selectedTypes.containsAll(subtypes)) {
				typesToSearch.removeAll(subtypes);