message: Add deprecation warning to tf.gfile.FastGFile.
  Fixes
diff: @@ -33,6 +33,7 @@ from tensorflow.python.lib.io.file_io import rename as Rename
  from tensorflow.python.lib.io.file_io import stat as Stat
  from tensorflow.python.lib.io.file_io import walk as Walk
  # pylint: enable=unused-import
  +from tensorflow.python.util.deprecation import deprecated
  from tensorflow.python.util.tf_export import tf_export
  @@ -52,6 +53,7 @@ class GFile(_FileIO):
  @tf_export('gfile.FastGFile')
  +@deprecated(None, 'Use tf.gfile.GFile.')
  class FastGFile(_FileIO):
  """File I/O wrappers without thread locking.
  