simplify shaderbase -- remove shaderproc -- no measurable speed diff

Bug: skia:
Change-Id: Id355e3e480847fe78f904735e59353c4eb3ba2bb
Reviewed-on: https://skia-review.googlesource.com/31560
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
6 files changed