When a user tries installing over a previous Firefox installation and Firefox Desktop is opened, the user will receive a prompt message indicating that Firefox is opened. This is not the case when Firefox Metro is opened. The installation continues and then requires a restart to complete the installation. Steps to reproduce the issue: 1) Open Firefox Desktop 2) Install Firefox once again and you will receive a prompt message indicating that the browser is currently opened 3) Repeat Step #1 & #2 using Firefox Metro instead and you will notice the installation will continue and require a reboot at the end Current Behavior: - Installing Firefox while Firefox Metro is opened will not produce an error message and will continue with the installation. A reboot is needed to complete the installation. Expected Behavior: - Warn the user if there's a Firefox Metro instance running in the background the same way Desktop Firefox does.

consideration for iteration #6

I was doing some testing on oak recently and was getting prompted.