Mode: force_next
Version: 52.0.2743.32
Reproduction Steps: 
1. Install extension via Chrome Web Store (e.g. https://chrome.google.com/webstore/detail/ireader/ppelffpjgkifjfgnbaaldcehkpajlmbc/related )
2. Click add > Install 
3. Note progress bar

Observed:
All text in download is repeated over and over until extension is downloaded/installed

Expected:
Only percentage to be read periodically or on demand