How to reproduce:
1. Open the attached project "case_1297458-Project.zip"
2. Make a WebGL build
3. Host the built WebGL Player
4. Open the Player in a browser
5. Open the Developer Tools (common shortcut F12)
6. In the Memory tab, take a snapshot
7. Inspect the allocated memory used
8. In the Player, click "Download 2MB file and unzip" a few times (3-5)
9. Take a memory snapshot again
10. Inspect the allocated memory used

Expected result: Memory is not increase
Actual result: Memory usage increases each time downloading and unzipping files

Reproducible with: 2018.4.30f1, 2019.4.18f1, 2020.2.2f1, 2021.1.0b2, 2021.2.0a1

Notes:
- Tested on Chrome and Firefox
- Chrome page crashes when unzipping larger files (ex. 43MB)