UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36

Example URL:
https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/clip

Steps to reproduce the problem:
1. goto https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/clip 
2. at the live example below, edit the code (like adding useless spaces, just want to trigger refreshing)
3. repeat 2. about 10 times

What is the expected behavior?
The page will be stucked for 2~3 seconds.

What went wrong?
Viewing Developer Tools > Performance, it says `ctx.clip()` costs such a long time. While firefox nightly (sorry for I only having this version of firefox) works well.

Does it occur on multiple sites: No

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 60.0.3112.113  Channel: stable
OS Version: 10.0
Flash Version: Shockwave Flash 26.0 r0