✅ Hide the share pill in visual tests, and re-enable tests that were flaky because of this

[newmuis]

Filed #20021 to track centralizing these fixes in one place, but this PR should fix the issues to unblock PRs.

Fixes #19890 by hiding this button entirely during tests.

/cc @rsimha

[newmuis]

@gmajoulet can you please also review the Percy diffs?

[gmajoulet]

LGTM except for: https://percy.io/ampproject/amphtml/builds/1277015/view/82556973/1440?mode=diff&browser=firefox&snapshot=82556973

[newmuis]

I think this is also WAI. Although it looks similar to the diffs we normally see, if you click on the "new" tab, you can see that it's actually just that the entire share pill is gone (which is what this PR intends to do)

[gmajoulet]

Oh right, thanks. I got confused because it looked a lot like the previous flakes...

[rsimha]

Thanks for fixing this!

[rsimha]

I'm surprised the tests passed for this PR. Pretty sure .i-amphtml-story-share-pill-label needs to be removed from loading_complete_css for each of these visual tests.

[gmajoulet]

You're right it'd be better to remove it. But could it still pass because, even if hidden, because the .i-amphtml-story-share-pill-label element is still present in the DOM?

[rsimha]

loading_complete_css is a list of CSS classes that the test runner waits for. If .i-amphtml-story-share-pill-label is removed, the test runner will still wait for the other CSS classes in that list.

[gmajoulet]

Yes, of course, I meant that the tests still pass because .i-amphtml-story-share-pill-label is still present in the DOM.

[rsimha]

Aha. Yes. :)

You could add it to the forbidden list if you want to make sure it's not on the page.