Lukas Woehrl 16359ec8ee Add feature to use percentage as value unit
Summary:
Adds the feature to use percentage as a value unit.

You can use the function ```YGPx(float)``` and ```YGPercent(float)``` for convenience.

I did some benchmarks:

```
Without Percentage Feature - Release x86:

Stack with flex: median: 0.000000 ms, stddev: 0.146683 ms
Align stretch in undefined axis: median: 0.000000 ms, stddev: 0.136525 ms
Nested flex: median: 0.000000 ms, stddev: 0.490101 ms
Huge nested layout: median: 23.000000 ms, stddev: 0.928291 ms

Stack with flex: median: 0.000000 ms, stddev: 0.170587 ms
Align stretch in undefined axis: median: 0.000000 ms, stddev: 0.143384 ms
Nested flex: median: 0.000000 ms, stddev: 0.477791 ms
Huge nested layout: median: 22.000000 ms, stddev: 2.129779 ms

With Percentage Feature - Release x86:

Stack with flex: median: 0.000000 ms, stddev: 0.132951 ms
Align stretch in undefined axis: median: 0.000000 ms, stddev: 0.136525 ms
Nested flex: median: 0.000000 ms, stddev: 0.489570 ms
Huge nested layout: median: 21.000000 ms, stddev: 1.390476 ms
Closes https://github.com/facebook/yoga/pull/258

Reviewed By: dshahidehpour

Differential Revision: D4361945

Pulled By: emilsjolander

fbshipit-source-id: a8f5bc63ad352eb9410d792729e56664468cd76a
2017-01-02 05:28:30 -08:00
..
2016-11-28 17:13:31 -08:00