[OpenJDK 2D-Dev] [9] RFR JDK-8152966: ClassCastException when adding IFD to the TIFFDirectory before the image write

[Brian Burkhalter]

Please review at your convenience.

Issue:	https://bugs.openjdk.java.net/browse/JDK-8152966
Patch:	http://cr.openjdk.java.net/~bpb/8152966/webrev.00/

Move the private method getDirectoryAsIFD(TIFFDirectory) from the API class TIFFDirectory to a public method in the internal class TIFFIFD and replace all casts such as

TIFFDirectory dir;
TIFFIFD ifd = (TIFFIFD)dir;

with

TIFFIFD ifd = TIFFIFD. getDirectoryAsIFD(dir);

Thanks,

Brian