mozilla/pdf.js — pull request #4482 by Snuffleupagus (2014-03-18 17:37:57+00:00)
Title: [WIP] Rewrite 'Preferences' to make it async

/cc @brendandahl Please look at this, and see if I'm on the right track with the rewrite.

This PR makes a number of changes to `Preferences`:
* Remove the class-like implementation, so that it's instead invoked once when the viewer loads.

This change is necessary if we want to support preferences for the viewer itself, and not just when opening documents. (The second commit makes use of this to add a pref to enable the hand tool by default.)
* Changes all functions to be asynchronous.
* Adds docs. Some of it might be unnecessary or too verbose, so feedback is welcome on this.

Fixes #4459.