Chrome Version       : 51.0.2704.22
OS Version: OS X 10.10.5
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari 9.1: Kind of slow too

What steps will reproduce the problem?
1. Open http://w3.salemstate.edu/~cmauriello/pdfEuropean/Paxton_Five%20Stages%20of%20Fascism.pdf
2. Scroll

What is the expected result?

Smooth scrolling


What happens instead of that?

Janky scrolling.


Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.22 Safari/537.36




(I couldn't find a great pdfium component...)