3e7f5fdd3f
When legacy-data-mixin.html is imported this will tell you on the console which observers need fixing regarding this change of behavior: https://polymer-library.polymer-project.org/2.0/docs/upgrade#update-observers This change was created by running this command line: find polygerrit-ui/app/ -type f | xargs sed -i '/^ is: / a\ _legacyUndefinedCheck: true,' Once all observers are fixed, this change will be reverted. This is tracked in https://bugs.chromium.org/p/gerrit/issues/detail?id=10723 Change-Id: Icccdfaa52bf77dfb25e949b2aa2402110f6c2276