Adding Command Flags to Chrome in Ubuntu?

Regarding the error message mentioned in post #21:
Please read the README file in /etc/apparmor.d/local. The profile I introduced to you is a translation of the Chromium profile with some additions which I found necessary. Line 129 in that profile refers to /etc/apparmor.d/local/opt.google.chrome.google-chrome - if that file doesn't exist on your system you'll get that error message.

That profile should work on any system - BUT you will probably need some more rules depending on your specific hardware or a different configuration. E.g., I have an Nvidia graphics card, therefore

/dev/nvidiactl rw,
/dev/nvidia0 rw,

is required. If you have an AMD or another card it will look different. Another example: Since I use Lastpass, the following rule was necessary:

@{HOME}/.lastpass/** k,

The necessary rules can be found with the help of the relevant error messages in /var/log/syslog.

I do not place these individual rules in /etc/apparmor.d/opt.google.chrome.google-chrome but rather in /etc/apparmor.d/local/opt.google.chrome.google-chrome as changes in my hardware or other configurations are easier to adapt.

If you prefer to add those rules to /etc/apparmor.d/opt.google.chrome.google-chrome instead and leave /etc/apparmor.d/local/opt.google.chrome.google-chrome empty (or alternatively delete line 129) - please do so. I myself find it easier to separate rules that should apply to any system from individual rules. But that's a matter of taste.

Whatever you do, with a handful of indivual rules that profile should work for you, too.

I hope these remarks clarify some confusion.