Chooser test
This page checks one thing: whether Google's full-page file chooser works in this browser. It can only change a test file named chooser-test.json, never a wedding plan.
1. Choose the test file
Google opens a page listing your files. Choose chooser-test.json, and you come back here.
2. Read and change it
Google may ask you to sign in again in a small window. Use the same account.