Use lazy initialization in autograd record_function to avoid static (#22317)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22317
About to add an observer that is also statically initialized in a different
file, so we need to enforce initialization order.
Reviewed By: ilia-cher
Differential Revision: D16012275
fbshipit-source-id: f26e57149a5e326fd34cb51bde93ee99e65403c4
