Summary: Fixes T8277. Transforming files can race; resolve the race after we lose.
Test Plan:
- Added `sleep(10)` near the bottom of the transform controller.
- Transformed a file in two browser windows at the same time; got something like this (exception corresponds to the loser of the race):
{F412526}
- Applied patch.
- Repeated process, got this:
{F412527}
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T8277
Differential Revision: https://secure.phabricator.com/D12965
d70ca6b7c8