+++ This bug was initially created as a clone of Bug #1472312 +++ Changes since last update: #9852 Proper Error Handling for Build Numbers of Downloaded Sources (Non-Git repositories). #9853 Fix re-rendering, using the same canvas, when rendering was previously cancelled (PR 8519 follow-up) #9859 Update translations and packages #9860 Update the localization README to indicate that the translations are imported from the Nightly channel #9858 Additional Scroll/Spread mode clean-up (PR 9832 follow-up) #9861 Refactor `PDFFindController` to use the 'pagesinit' event, dispatched on the `eventBus`, to resolve the `_firstPagePromise`

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/5d23b6e0b74d Update pdf.js to version 2.0.661. r=bdahl