Summary:
In D21788243, John suggested the field should be calculated when needed not precomputed. This diff does so by moving calculation logic to the component and removing the field
This also fixes the crashing bug when switching to Structure tab, changing table, and switching back to Data tab.
Reviewed By: mweststrate
Differential Revision: D21906983
fbshipit-source-id: 5a9522a5ba3f504108282fb27deae25b5eadc693
a50c373631