Remove LegacyPromise
Remove LegacyPromise in src/core/worker.js
Merge pull request #4728 from Snuffleupagus/remove-LegacyPromise-worker.js

Remove LegacyPromise in src/core/worker.js
Merge pull request #4729 from Snuffleupagus/remove-LegacyPromise

Remove LegacyPromise