RFR: 8320965: Scrolling on a touch enabled display fails on Wayland [v2]

[Jose Pereda]

On Mon, 18 Dec 2023 10:34:02 GMT, Thiago Milczarek Sayao <tsayao at openjdk.org> wrote:

>> The check is to allow compilation and test on Ubuntu 16.04 - When shipping the final build it should be built on gtk 3.20+, so both dlsym and the check makes sense. 
>> 
>> So when running on Ubuntu 16.04:
>> - For testing on the platform, the #ifdef will make it possible to compile;
>> - For running the released built (which should be built on gtk 3.20+) dlsym will fail and fallback;
>
> That's only if we want to keep building working on 16.04. I think it makes easier to test on it.
> But, it's already failing for Platform preferences API code.

In any case, if `GdkSeat` is available only since 3.20, then we need to add the compile-time checks anyway, since minimum supported is 3.8.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1305#discussion_r1429891858