Merge "adb: use a custom thread to poll for usb devices on mac." am: 09c5fcf am: 507f38f
am: e618f6c

* commit 'e618f6cb367b83774274786bc28badae34a6c638':
  adb: use a custom thread to poll for usb devices on mac.

Change-Id: I15e524743bdf8b855374c80dc9b05bc1ce03441b