Add 'shader' as an alias for 'fragmentProcessor'

Change-Id: I2d95c63de18125e6258709b48b03abd7904b7537
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/278596
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
10 files changed