VideoBlockEditor:Poster Modal

Build 4622 on 23-01-DC-feat-image-source
360px
Reviewing disabled
Baseline History
Build 4622f4cda93
Current build. There are unaccepted changes, so build 3684 is still the baseline.
Build 2974a810b55
Accepted by John Geronimo.
Build 1826795d939
Accepted by John Geronimo.
Build 1773515e4f5
Accepted by Siyang Cao.
Commenting is disabled because there's a newer build on this branch