Boosted by the most-watched episode of Modern Family ever, Matthew Perry’s new ABC sitcom Mr. Sunshine drew a healthy sampling Wednesday night: 10.6 million viewers and a 3.7 rating among audiences under 50. That’s encouraging, but hardly cause for folks at the Alphabet to be walking on sunshine (sorry!). True, this was ABC’s best debut for a new show this season, but given that everything else the network’s tried out this season has pretty much flopped, that’s not saying much. Sunshine did outrate last fall’s season premiere of usual 9:30 p.m. time-slot occupant Cougar Town — but only by 9 percent. Given the huge amount of promotion ABC put behind Sunshine, along with the record tune-in for Modern Family, a single-digit increase over Cougar Town isn’t really surprising. Sunshine also lost 26 percent of its Modern Family lead-in (a bit better than Cougar Town’s retention last fall, but not by much). As with all new shows, the real test for Sunshine will be how it holds up in the coming weeks, when ABC’s promotional spotlight fades and viewers get a chance to embrace or reject the show.