[jfx25] RFR: 8363813: Missing null check in GlassScreen

[Kevin Rushforth]

On Wed, 23 Jul 2025 23:45:12 GMT, Ambarish Rapte <arapte at openjdk.org> wrote:

> Clean backport of adding simple null checks in glass screen fix to the `jfx25` stabilization branch.

Looks good to go into jfx25.

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Marked as reviewed by kcr (Lead).

PR Review: https://git.openjdk.org/jfx/pull/1854#pullrequestreview-3049726975