UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce the problem:
1. Open a pdf (around 15 MB) slides file 
2. Click the button "fit to width" to start viewing the slides
3. Press the left and right arrow to go to previous and next page

What is the expected behavior?
The page transition should be fluent and fast.

What went wrong?
However, it could take one to two second to turn a page, which is far to slow.

Did this work before? N/A 

Chrome version: 61.0.3163.100  Channel: n/a
OS Version: OS X 10.13.2
Flash Version: 

I compared with Firefox and the page turning is very fast there with the same pdf file.