Fully remove coord transform precision code

Coord transforms are always computed and interpolated at high precision.

Bug: skia:
Change-Id: I5f7eadc2080df8ad5cbb080835c0dba09c59e63e
Reviewed-on: https://skia-review.googlesource.com/11180
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
9 files changed