Storage Access Headers Case

Steps to Reproduce

1. Create keys and certificate for HTTPS. In this folder, run the following commands (requires openssl)
2. openssl req -x509 -newkey rsa:2048 -keyout keytmp.pem -out cert.pem -days 365
3. openssl rsa -in keytmp.pem -out key.pem
4. Run npm install to install dependencies (express, cookie-parser).
5. Run npm start to start the app at http://localhost:3000.
6. Open iframe.html and follow the instructions, or follow these steps manually:
7. Visit http://localhost:3000/cookie to set a cookie with a name and value of your choice. If you visit http://localhost:3000 (outside of an iframe), you should see the cookie you just created.
8. Open http://localhost:3000?embed in an iframe (make sure to include the embed query parameter).
9. When prompted to grant storage access, grant access.
10. As with the non-iframe version, you should now see the cookie you created (assuming storage access was granted in step 3).