RFR: 8265835: Exception in Quantum due to null platformWindow

[Ambarish Rapte]

On Wed, 2 Nov 2022 17:05:10 GMT, Lukasz Kostyra <duke at openjdk.org> wrote:

> Reproduction code was not provided, I wasn't able to reproduce the circumstances in which the issue occurs. On our side it seems like `WindowStage.getPlatformWindow()` will not return null, however it is also difficult to reject the possibility that some custom user code might trigger an edge-case where a null will be returned.
> 
> Adding these checks is not an intrusive change to our code, it is in fact an extra null-check added to already existing checks, but it might prevent the exception from appearing in the future.
> 
> I checked other places in our code using `WindowStage.getPlatformWindow()` and none require a null check.

LGTM

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Marked as reviewed by arapte (Reviewer).

PR: https://git.openjdk.org/jfx/pull/935