Clean backport to jfx11u. Tested on all three platforms, along with my other in-progress backports, all of which are aggregated in my [`kevinrushforth:test-kcr-11.0.12`](https://github.com/kevinrushforth/jfx11u/commits/test-kcr-11.0.12) branch.
------------- Commit messages: - 8259356: MediaPlayer's seek freezes video Changes: https://git.openjdk.java.net/jfx11u/pull/10/files Webrev: https://webrevs.openjdk.java.net/?repo=jfx11u&pr=10&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8259356 Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod Patch: https://git.openjdk.java.net/jfx11u/pull/10.diff Fetch: git fetch https://git.openjdk.java.net/jfx11u pull/10/head:pull/10 PR: https://git.openjdk.java.net/jfx11u/pull/10
