Bug 213040 [Markers] Selected filters not being kept on restart
When I select "Warnings on Selection" and then restart it is not selected when I come back in. We need to retain these selections. Note this is only a problem when selecting from the menu - from the dialog works fine.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/MarkerContentGenerator.java
* Return all of the projects being shown.
	 * 
	 * @param focusResources
	 * @return IResource[]
	 */
	private IResource[] getProjects(IResource[] focusResources) {
		if (focusResources.length == 0)
			return EMPTY_RESOURCE_ARRAY;
		HashSet projects = new HashSet();
		for (int idx = 0; idx < focusResources.length; idx++) {
			projects.add(focusResources[idx].getProject());
		}
		if (projects.isEmpty())
			return EMPTY_RESOURCE_ARRAY;
		return (IResource[]) projects.toArray(new IResource[projects.size()]);
	}
	/**
	 * Get the resources in working set.
	 * @param workingSet
	 * @return IResource[]
	 */
	private IResource[] getResourcesInWorkingSet(IWorkingSet workingSet) {
		if (workingSet == null) 
			return new IResource[0];
		
		if (workingSet.isEmpty()) 
			return new IResource[] { ResourcesPlugin.getWorkspace().getRoot() };
		IAdaptable[] elements = workingSet.getElements();
		List result = new ArrayList(elements.length);
		for (int idx = 0; idx < elements.length; idx++) {