Use a consume load in SkLazyPtr.

This only affects ARM, where an acquire needs a memory barrier but consume does not.  I am interested to see if there's a noticeable effect on the Android bots.

BUG=skia:

NOTRY=true
R=bungeman@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/381143002
4 files changed