As your log shows, libflac12t64 and libopenh264-7 were installed from testing, not sid. Sid has libflac14 and libopenh264-8.
- Bug#1099210: chromium: Uninstallable on sid due... Guillem Jover
- Bug#1099210: chromium: Uninstallable on si... Tobias Frost
- Bug#1099210: chromium: Uninstallable o... Fiona Klute
- Bug#1099210: chromium: Uninstallab... Tobias Frost
- Bug#1099210: chromium: Uninstallable o... Andres Salomon
- Bug#1099210: chromium: Uninstallab... Sjoerd Simons
- Processed: Re: Bug#1099210: chromium: Unin... Debian Bug Tracking System
- Bug#1099210: marked as done (chromium: Uni... Debian Bug Tracking System
