These methods were deprecated in 7.0, now we can remove them.

R=adamk@chromium.org

Bug: v8:7868
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I60badb378a055152bdd27aed67d11ddf74fce174
Reviewed-on: https://chromium-review.googlesource.com/1209283Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55695}