jquery/jquery — pull request #1021 by chadparry (2012-11-07 23:14:36+00:00)
Title: Refactor timer initialization, ticket #12837

Each step of each animation should not need to check `fxNow`. Instead, the time can be queried once at the beginning of `jQuery.fx.tick`. This also solves an iPad bug where an event for clearing `fxNow` was being dropped, resulting in a never-ending animation.

Note that the new unit test passes both before and after my patch is applied. The only way to exercise the bug is if the user is in Safari and pinches to zoom a colorbox before the animation starts. The test is probably still useful for verifying that synchronized animations work as advertized.

This is a continuation of [pull request #1015](https://github.com/jquery/jquery/pull/1015).

/cc @gibson042 @gnarf37