Affected Version:

What steps will reproduce the problem?
1. Navigate Safari to https://chromium-review.googlesource.com/c/infra/infra/+/912763

What is the expected output?

One "Tryjobs" section. One <cr-buildbucket-view> element in dev tools.

What do you see instead?

Two "Tryjobs" sections. Two <cr-buildbucket-view> elements in dev tools.

Please provide any additional information below.

Same thing on Chrome for iPhone (which is, FWIU, has to use Safari engine)
Does not happen on Chrome.

Using Safari debugger I've verified that line

  plugin.registerCustomComponent(
        'change-view-integration', 'cr-buildbucket-view');

in buildbucket.js is executed only once.