am 03403712: Merge "DO NOT MERGE Add null check before disconnecting a device." into gingerbread

Merge commit '0340371297887290d7593d7c346e422a4c9ecd1a' into gingerbread-plus-aosp

* commit '0340371297887290d7593d7c346e422a4c9ecd1a':
  DO NOT MERGE Add null check before disconnecting a device.