am 4ec6d1c7: Fix bug in SkJPEGImageDecoder.

Merge commit '4ec6d1c74c7ecbfd07adaec3810d64531a79b532'

* commit '4ec6d1c74c7ecbfd07adaec3810d64531a79b532':
  Fix bug in SkJPEGImageDecoder.