Hard code bicubic coefficients in the shader

BUG=skia:

Change-Id: Ie231a9bd2ea2083005a595e9e426590da740b2ed
Reviewed-on: https://skia-review.googlesource.com/6619
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed