Merge "Rename vars and functions from 'glslcaps'->'shadercaps'" into master-skia

https://skia.googlesource.com/skia/+/1edc5b92fecefb79f01cf0e302646eacf32b06c7

Change-Id: Ib101a1ae9837e215a69b645a0325bfb09fb7f3be