Comment 6 for bug 988337

This type of thing happens with me as well. I am using Chrome, not Chromium, but it is the same type of behavior.

My setup:
Ubuntu 12.04 64-bit
google-chrome is default browser
google-chrome is also default program to open html files
google-chrome is locked to launcher

To produce:
I open google-chrome and browse
I then locate an html file on my drive in nautilus and double-click to open it

Expected behavior:
"locked" Google chrome icon shows multiple arrows, indicating that multiple windows are now open

Actual behavior:
A second chrome icon shows up at the bottom of the launcher, which is attached to this html file open instance

Ideal behavior:
The single chrome instance opens a new tab showing the html output. I realize this is likely possible now, and perhaps just related to calling chrome in a special fashion to indicate it should attach it as a new tab instead of a new instance. But let's just get the new instance thing working first!! :)

Additional info:
I don't believe I modified any mime or defaults information manually (in the config files) when setting chrome to the default html opener. Though this definitely looks like confusion between desktop files/bamf and google-chrome reporting itself funny when opened from a file.