In  bug 863094  we changed the inactive window colors.  We should also change the tints similarly (so the default frame color tinted with FRAME_INACTIVE becomes the default inactive frame color).

This way themes will match Chrome's default behavior.

Added bonus: we can probably remove the hardcoded inactive/incognito inactive frame colors and use the tints to calculate the defaults too.  Then future maintenance is easier because they won't get out of sync.