Summary:
Followup of D39772453 (2437aeb3e9)
Fixes https://fb.workplace.com/groups/flippersupport/permalink/1518236858656967/
1. Stop using clientWidth and offsetWidth because they have rounding errors
2. Since step 1 did not resolve the issue entirely (for some weird reason I do not really have the capacity now to investigate - my bet it is a rounding error when you sum up doubles) set offset of the table to "scroll" instead of "auto". As a result, it starts rendering space for the scrollbars all the time, but since Flipper is a dev tool it should be fine
Reviewed By: antonk52
Differential Revision: D41839402
fbshipit-source-id: cf50eb1600b692d3970003fd1b45b953ee45e3df
10e415655c