Trigger tab preview based on frame key

[cezaraugusto]

• Auditors: @bsclifton, @luixxiul
• Close: Tab preview on hover doesn't work after closing tab until moving the mouse out of tabs bar #7606

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Test Plan:

When next tab exists

Static ordering

1. Open 3 tabs with different websites
2. Make first active
3. Hover over second
4. Close it
5. Third tab (now second) should show as a preview

dynamic ordering

1. Open 3 tabs with different websites
2. Ensure you reorder tabs by drag-n-drop
3. Make first active
4. Hover over second
5. Close it
6. Third tab (now second) should show as a preview

when previous frame is not active

1. Open 5 tabs
2. Make third active
3. Hover over fourth
4. Close it
5. Fifth tab (now fourth) should show as a preview

when next tab is null

1. Open 3 tabs with different websites
2. Close the 3rd tab
3. no preview is triggered

when frame is closed by close tab shortcut

1. Open 3 tabs with different websites
2. Make first active
3. Close it by shortcut (cmd/ctrl+w)
4. No preview is triggered

Reviewer Checklist:

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[luixxiul]

The test plan works.

[cezaraugusto]

works as-is but a new state is needed from #8852 so setting as blocked until that is approved

[bbondy]

Pls rebase and remove the needs rebase tag when done. Thanks.

[cezaraugusto]

rebased, removed PR/blocked tag as well I'll rework #8852 if needed, if this is approved first

[luixxiul]

the test plans work.

[bsclifton]

Change works great! 😄

If you had time available, it would be awesome to have a test to make sure this behavior doesn't accidentally regress

[luixxiul]

Is this change covered with automated tests?

[cezaraugusto]

@luixxiul I didn't include new ones but they are covered with existing tests for tab previews

[luixxiul]

@cezaraugusto the question occurred to me because of the issue here: #10103

[cezaraugusto]

ok np, that's related thanks for opening