General idea of the fix: skip the whole draw manager callback madness which
was used to tag object's engine specific data as dirty. Use generic recalc
flag in ObjectEngineData structure instead. This gives us the following
benefits;
- Sovles mentioned bug report.
- Avoids whole interface lookup for opened viewports for EVERY changed ID.
- Fixes missing updates when viewport is temporarily invisible.
Reviewers: dfelinto, fclem
Differential Revision: https://developer.blender.org/D3028
9577ebde79