Merge "adb: use a custom thread to poll for usb devices on mac." into nyc-dev
am: f7c31b9

* commit 'f7c31b9552da778ebea5ac3c2bd3c5260b5e7705':
  adb: use a custom thread to poll for usb devices on mac.

Change-Id: I6fb6686525a9e67f2a12be955d4a1692eeb5ab6a