Changes since the last update: #2510 Add word wrap of text in the Outline view to avoid horizontal scrolling #2499 Refactors rescaleImage: improving quality of scanned images #2511 Fixes the Outline view in RTL languages, follow up of #2510 #2463 Remove cid dictionary values for normalized fonts. #2521 Temporarily remove cid_cff test file. #2454 Tests presence of the xhr-response in the worker #2505 Refactors encodeFloat, font matrix and flex args #2520 Disables *Blue* values when HINT_ENABLED == false #2525 Traces pdf.js version #2500 Add support for more Type1 private dictionary entries. #2526 Fixes creation of OS/2 table #2540 Handle broken hex string #2538 Update zh-TW translation #2551 Updated Japanese locale #2548 Fix isDict when type is missing in dictionary. #2562 Fix a problem about Japanese PDFs without embedded fonts #2547 Support corrupted pdfs that are encrypted but lack 'ID' in trailer #2566 Handle missing 'FontName' entry in FontDescriptor object #2549 Skip commands that have too few arguments #2574 Change page with up/down arrow keys when zoom is set to 'page-fit' #2571 Do not error when an EndOfPage segment is encountered in jbig2 #2567 Supports 'H/V', 'EUC-H/V' and '90ms*' CMaps #2509 Add various improvements to scroll Thumbnails into view #2557 Default to a built-in font if an invalid non-embedded font is encountered #2585 Updated Chinese Simplified (zh-CN) locale

Any chance this would be appropriate to backport to Firefox 20 (currently aurora, moving to beta next week), as well? (It fixes bug 831468, which appears to be a regression that was introduced in Firefox 20, and was then fixed in 21 by this bug)