tree c4128bfc0af4d9449995bba7650d1a912c126245
parent 96f12377942dbe1c6b1d0ffa7d626d99cb265443
author Behdad Esfahbod <behdad@fb.com> 1553642283 -0700
committer Behdad Esfahbod <behdad@fb.com> 1553642620 -0700

Use class templates for Null objects

This allows partial-instantiating custom Null object for template Lookup<T>.
Before, this had to be handcoded per instantiation.  Apparently I missed
adding one for AAT::ankr.lookupTable, so it was getting the wrong (generic)
null for Lookup object, which is wrong and unsafe.

Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=944346