Thanks everyone for the response...I tried several flags: '--silent', '/silent', '--no-first-run', 'skip_first_run_ui' etc.. None of them works while installing chrome using mini_installer.exe...I was always getting first launch of chrome related dialogs.
Finally, after speaking to Omaha Test team, I was able to learn that if you pass flag '--do-not-launch-chrome' to mini_installer.exe, it doesn't launch chrome and installation happens silently. After that, one can start chrome with '--no-first-run' and it works like a charm without any dialogs..
I am still looking for some similar flag for uninstall. Currently, uninstall comes with user dara dir delete confirmation dialog. I want to suppress that. Any ideas for silent uninstall flag ?
Thanks,
Tejas