Auto merge of #1054 - sotaroikeda:border-glsl, r=glennw
Auto merge of #1054 - sotaroikeda:border-glsl, r=glennw

Make non-empty case statements have break or return

Fixes  #1044

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/webrender/1054)
<!-- Reviewable:end -->

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender