orderBy speed optimization

[agentcooper]

I made a speed optimization to the orderBy filter utilizing the schwartzian transform.

Here is the jsPerf: http://jsperf.com/orderby-speed-optimization

And here is the diff: https://github.com/agentcooper/angular.js/commit/d20a9e65eb2a4fdf9f935636c5c278212e3d09cc (not sending a pull request yet, because tests are currently broken in master :-( Can we fix it?)

[jamesdaily]

Tests should be unbroken now, assuming you're referring to the Firefox SauceLabs issue.

[agentcooper]

@jamesdaily thanks for the information

[btford]

I poked around the benchmarks too. I noticed in the original benchmark that the items are sorted. Here's one with randomized item values: http://jsperf.com/orderby-speed-optimization/2

overall, looks good!

[solidspark]

+1 for this. Optimizations of this nature are needed.

[iamsebastian]

+1. Would be a great addition.

[Narretz]

Fixed in 48e1f56