Align all SkRecord::alloc() calls up to at least a pointer size.

This should make the LSAN bots able to see all our pointers.

BUG=skia:
R=reed@google.com, robertphillips@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/517073002
3 files changed