ContentHostingService should implement a new method as follows, to address issues described in SAK-14165:

        /**
        * Retrieve a collection of ContentResource objects of a particular resource-type in a set of contexts
        *
        * @param resourceType select resources where CONTENT_RESOURCE.RESOURCE_TYPE_ID equals resourceType
        * @param context select resources where CONTENT_RESOURCE.CONTEXT in [context,...]
        * @return collection of ContentResource
        */
       public Collection<ContentResource> getContextResourcesOfType(String resourceType, Set<String> contextIds);