Apparently the easiest/only way to force Maya to use Chrome ( or firefox) is to update your registry and force it to use it..
this little bit of python code should do the trick.
import _winreg
htm = _winreg.OpenKey(_winreg.HKEY_CURRENT_USER,"SOFTWARE\\Classes\\.htm", 0, _winreg.KEY_ALL_ACCESS)
_winreg.SetValueEx(htm, '', 0, 1, "ChromeHTML")
_winreg.CloseKey(htm)
