Summary:
- Prevent the GC from collecting MeasureInternal in order to call managed MeasureFunction properly from unmanaged
- TestMeasureFuncWithDestructor will fail without the fix
- Avoid new as C implementation
Reviewed By: emilsjolander
Differential Revision: D4080765
fbshipit-source-id: d58fa18f6f74012aeda5dd15dfa7ceb0b64584d0
1ba81d9ec7