UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.63 Safari/537.36

Steps to reproduce the problem:
1. Open a document with a large number of pages.
2. Start scrolling by dragging the scrollbar handle.
3. Initially the current page number is visible and updated in the top overlay (e.g. "Page 25 / 9000")
4. But after some time the top overlay is hidden, even if the user is still scrolling.

What is the expected behavior?
The top overlay should be visible and show the current page number for rapid scrolls (as when the scroll handle is dragged in a large document).

What went wrong?
The top overlay is hidden. I remember that before the PDF viewer switched to material design, the page number was shown in a small overlay near the scroll bar. This is no longer the case.

Note that if the document is large (e.g. 1,000 pages) it is very difficult to scroll to a given page (say 667) if I cannot see the page number. Even if pages are numbered in the PDF, because when scrolling so fast I cannot see them; so I need to stop, read the number, scroll again; repeat.

Did this work before? N/A 

Chrome version: 51.0.2704.63  Channel: stable
OS Version: 
Flash Version: Shockwave Flash 21.0 r0