[Auth] Add popup WebDriver tests (duplicated from the redirect tests)

[sam-gc]

No description provided.

[changeset-bot]

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Latest commit: c5e0284

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[google-oss-bot]

Binary Size Report

Affected SDKs

No changes between base commit (1de07ba) and head commit (ac94ca2).

Test Logs

• Base (1de07ba8): https://github.com/firebase/firebase-js-sdk/actions/runs/646880963
• Head (ac94ca2c): https://github.com/firebase/firebase-js-sdk/actions/runs/646896111

[google-oss-bot]

Size Analysis Report

Affected Products

No changes between base commit (1de07ba) and head commit (ac94ca2).

Test Logs

• Base (1de07ba): https://github.com/firebase/firebase-js-sdk/actions/runs/646880963
• Head (ac94ca2): https://github.com/firebase/firebase-js-sdk/actions/runs/646896111

[yuchenshi]

what does this do?

[sam-gc]

In popup.js and redirect.js, I was previously assigning state to the window directly (things like errorCred). I didn't want that to clash by using it in multiple files (it applies to both popup and redirect) so I started putting it on these objects (window.redirect.errorCred and window.popup.errorCred). That doesn't work though if you make window.popup the imported module directly.