Re: [w3c/webcomponents] Provide a lightweight mechanism to add styles to a custom element (#468)

Update from Blink:
We've implemented the fake-shadow-root approach [here](https://chromium-review.googlesource.com/c/chromium/src/+/992074), and the UA version [here](https://chromium-review.googlesource.com/c/chromium/src/+/1068562).

We've also compared the performance (more detailed doc about comparison is [here](https://docs.google.com/document/d/1aA1emBlA20nVB0bmkcamjFdPEvcoBuRbp6p8QKcPz80/edit?usp=sharing#heading=h.nydsf4pbpbex)).

- There isn't a significant difference in performance between the UA vs fake-shadow-root approach when the number of elements are in the hundreds.
- When there are thousands of elements the UA approach is a bit slower but not by much, around or less than 3% slower.
- They are both much faster than using shadow root + <style> element.

>From implementation perspective, the UA approach is simpler, because in the fake-shadow-root version we are doing some things differently when there's a real shadow root or not on the custom element.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/468#issuecomment-394618751