Revert "Revert "Switched highp float to highfloat and mediump float to half.""

This reverts commit 1d816b92bb7cf2258007f3f74ffd143b89f25d01.

Bug: skia:
Change-Id: I388b5e5e9bf619db48297a80c9a80c039f26c9f1
Reviewed-on: https://skia-review.googlesource.com/46464
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
132 files changed