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
returnMarkers = new HashSet(matching);
					else
						findIntersection(matching, returnMarkers);
					matching.clear();
				}
			} else {
				returnMarkers = new HashSet();
				while (filtersIterator.hasNext()) {
					computeMarkers(returnMarkers, subMonitor,
							(MarkerFieldFilterGroup) filtersIterator.next(),
							focusResources);
				}
			}
		} else
			returnMarkers = computeAllMarkers(subMonitor);
		MarkerEntry[] entries = new MarkerEntry[returnMarkers.size()];
		Iterator markers = returnMarkers.iterator();
		int index = 0;
		
		while (markers.hasNext()) {
			entries[index] = new MarkerEntry((IMarker) markers.next());
			index++;
		}
		return new MarkerMap(entries);
	}
	/**
	 * Get the all of the fields that this content generator is using.
	 * 
	 * @return {@link MarkerField}[]
	 */