For correct results these must have been set already when the depsgraph was
created and evaluated, so all dependencies have appropriate resolutions too.
For particle we no longer backup and restore the viewport particles to avoid
overwriting them during render, as copy-on-write solves this for us. Even
without COW particles seem to work ok.
This also removes the particle simplification options based on camera. This
was never used much and only available in Blender Internal.