Based on http://pastebin.mozilla.org/3061694
1. Remove "debug helpers" and use console.log/console.warn directly (top).
2. Remove page load initialization (middle).
3. Remove window._ alias (bottom)
The original diff contained an extra entry
"Adds fallback argument to the getL10nData;",
but this was already implemented in the rebased webL10n, so it's no
longer PDF.js-specific.