Javadoc incremental search for packages and classes
As of
To have this extension apply to file:// URLs, open the about:config page and set greasemonkey.fileIsGreaseable to true.
Also available as a Google Chrome extension: https://chrome.google.com/webstore/detail/javadoc-search-frame/mfgkihmpcjjnijmkchojlbccbmhcdfcd
