In bug 583359 we have landed the ability to filter messages in the Web console, based on strings and message types. The tests we've landed are somehow broken - see browser_webconsole_live_filtering_of_message_types.js and browser_webconsole_live_filtering_on_search_strings.js. Both tests always check for 0 messages, irrespective of their filter criteria. These tests do not fulfill their purpose and they do not catch any kind of relevant regressions. We need these fixed.