rem: return /^text\/|\+xml$/.test(contentType); 
add: return /^text\/|\+xml$/.test(contentType) || contentType == "application/x-javascript" || contentType == "application/xml" || contentType == "mozilla.application/cached-xul"; 
context:   mimeTypeIsTextBased : function(contentType)  {    return /^text\/|\+xml$/.test(contentType);  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/2b70baf55cc95dc76561d642c57d73be4d386591/nsBrowserStatusHandler.js/buggy/xpfe/browser/resources/content/nsBrowserStatusHandler.js