This PR replaces 2 deprecations which were added in https://bugs.openjdk.java.net/browse/JDK-8188026
------------- Commit messages: - 8278425: TreeTableCellStartEditTest uses deprecated TreeTableCell methods Changes: https://git.openjdk.java.net/jfx/pull/692/files Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=692&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8278425 Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod Patch: https://git.openjdk.java.net/jfx/pull/692.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/692/head:pull/692 PR: https://git.openjdk.java.net/jfx/pull/692
