Remove SK_SUPPORT_LEGACY_RP_BLENDS-guarded code

The flag is no longer used.

Change-Id: I39156ef5683538263c2302f2fe3ba779e55dbc47
Reviewed-on: https://skia-review.googlesource.com/38360
Commit-Queue: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
1 file changed