Auto merge of #16795 - mrobinson:out-of-viewport-transform, r=glennw

Don't optimize display list for projective transforms

There are situations where elements are transformed from outside the
display list. With projective transforms it's currently difficult to
detect these. In those cases we just don't optimize the display list,
so that they will always be shown.

Fixes #13822.

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- [x] These changes fix #13822 (github issue number if applicable).

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