am 0249c83e: am 31a69fdb: throw if we have a null typeface native instance (so...

am 0249c83e: am 31a69fdb: throw if we have a null typeface native instance (so we don\'t crash in native code) we may still have to native-destroy a Typeface with a null ref, so check for that

Merge commit '0249c83e'

* commit '0249c83e':
  throw if we have a null typeface native instance (so we don't crash in native code)