remove legacy vertices virtual from SkDevice

BUG=skia:6366

Change-Id: I9fb49538f358343a7c2e4541d0044d961ac1b54d
Reviewed-on: https://skia-review.googlesource.com/9870
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
13 files changed