Steps to reproduce:

1. Create new project
2. Set pivot mode to center
3. Add Scroll View to scene
4. Select it in hierarchy and start duplicating it by holding down ctrl+d
5. Notice that pivot point uses only one of three Scroll View children (viewport, horizontal scroll bar and vertical scroll bar) instead of calculating center for all of them collectively

Reproduced with: 2017.2.0p3, 2017.3.0b10, 2017.1.0a5
Not reproducible: 2017.2.0p2