Prior to this CL, we always used raster-pipeline if the device had a
colorspace. In this CL, we defer to individual shaders to decide if they can still
use the legacy path (onMakeContext).
The motivation is purely performance (and perhaps short-term backwards
compat): the legacy blits are usually faster, so staying in them
(as long as we still draw correctly) is preferable.
Causes some (mostly unimportant) rebaselines, esp. around bilerp, as the
rasterpipeline does a much better (but slower) job of it, and now we will
use the legacy bilerp more often.
Bug: skia:8793
Change-Id: I1e7e482a863a1a09ffef86a87e2aa9a4a8d1b9b5
Reviewed-on: https://skia-review.googlesource.com/c/195888
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
011d166d37