Something of note
0- Atk Skarmory Brave Bird vs. 0 HP / 4 Def Mega Pinsir: 168-198 (61.9 - 73%)
+2 252 Atk Aerilate Mega Pinsir Return vs. 252 HP / 252+ Def Skarmory: 140-165 (41.9 - 49.4%) -- 25.4% chance to 2HKO after Stealth Rock and Leftovers recovery
Granted, Skarmory is probably coming in when you SD so this may not be so important, but with just a tiny bit of prior damage or if Skarm has had lefties knocked off you 2HKO Skarm with +2 return, not even necessitating close combat to defeat it. Skarmory can't OHKO you with Brave Bird like it can when you get the defence drop from CC, so you don't need CC to beat Skarm at all.
Granted, you're still going to want to run CC for Rotom, balloontran/drill and Ttar, but if you're like super duper scared of physically defensive Doublade or some shit you can use Earthquake if you'd really like.
Edit:
Just realized that unless Skarm is switching into you while you're already at +2 and attacking it can just roost stall you anyway rather than Brave Birding you. So unless it's spdef skarm disregard busting through Skarmory with return.