Version: 56.0.2917.0 
OS: OSX El Capitan

I have these two pdfs open:
1) http://www.orangepi.org/download/orange_pi-lite-v1_1-schematic.pdf
2) dl.linux-sunxi.org/H3/Allwinner_H3_Datasheet_V1.0.pdf

The tabs are in background, I am not interacting at all with the pdf, which was loaded ~20 mins ago.  CPU usage is very high, close to 90%, although the pdf are fully usable, I can scroll and zoom them. The main problem is that my laptop is burning my legs and my battery is draining.
From task manager I see that the process using cpu is: "MimeHandler: name of pdf"

Attaching a spindump.

I also captured a trace (https://drive.google.com/open?id=0B1oJWfrTOXwxdkstRHVWNUtueVk).
The process in question is PID 55117. The main thread of that seems hammered by timers.
 

Deleted: Google_Chrome_Helper_55117.spindump.txt 3.6 MB

Google_Chrome_Helper_55117.spindump.txt 3.6 MB View Download