viewBox attribute is set only once and is not updated on map refresh.
Steps to reproduce:
1. Create a map (300x300 px).
2. Open map.
3. In another tab, change map size to 600x600 px.
4. Wait for map to be reloaded.
5. Observe that map is resized to 600x600 px, but viewBox stays "0 0 300 300".