Test failures - Scene/PointPrimitiveCollection

I'm seeing these test failures in master in Chrome. @lilleyse @IanLilleyT do you see these failures?

```
Scene/PointPrimitiveCollection picks a pointPrimitive using scaleByDistance
Expected to pick undefined, but picked: [object Object]
at http://localhost:8080/Specs/Scene/PointPrimitiveCollectionSpec.js:714:23
```

```
Scene/PointPrimitiveCollection renders pointPrimitive with scaleByDistance
Expected to render [0,0,0,255], but actually rendered [0,255,0,255].
at http://localhost:8080/Specs/Scene/PointPrimitiveCollectionSpec.js:201:23
```

Start by running Specs/Scene/PointPrimitiveCollectionSpec.js in Chrome and reproduce the failures reported at lines 714 and 201. Trace the affected PointPrimitiveCollection behavior from those tests; done means both scaleByDistance tests produce the expected pick and rendered color results.

Written by the indexing model from the issue text.