Steps to reproduce:

1. Open a long page.
2. Make a change near the top.
3. Without scrolling to another part of the page, click "Save" in the toolbar.
4. Watch the page (behind the Save dialog box) scroll all the way to the end.

Expected behavior:

1. Open a long page.
2. Make a change near the top.
3. Without scrolling to another part of the page, click "Save" in the toolbar.
4. Page stays put. When the page has been saved, the page is at the spot

Reproducible in every single edit in Safari version 10.0.1 (12602.2.14.0.7) on macOS Sierra 10.12.1. Not reproducible in Firefox 50.