b/16380611. Check for null Account objects before using.

It seems that there is a timing issue where the account is
deleted during onPerformSync(). Since we don't check for
a null Account.  We crash. A null return value from
restoreXYZFromId() is valid so we should handle it.

Change-Id: I333090f6f8e69c555ab765aa58406f29300a3126
3 files changed