You can really use any site to replicate it that has custom webkit scrollbars, even this example here:
https://css-tricks.com/examples/WebKitScrollbars/

Simply enable mobile emulation and you can't grab it.

Do you mean "toggle device mode" in the devtools by "mobile emulation"?

Yes, the button next to select element in dev tools which let's you change between different devices and also uses touch events instead of mouse events (touchstart instead of click). You can also just use an Android device. I have a Nexus 6P and its the same on it. But since I can also replicate on desktop Chrome while using this device mode, I know it's something in Chrome.

I believe this is an aspect of how touch simulation works from Devtools. You are able to drag it the first time the page is transitioned from opening devtools but if you refresh it you can no longer drag the scrollbar.

Dmitry any idea?

Thank you for your reply.

When you refresh, it then properly sends touch commands instead. But please remember I am also able to replicate this on my Nexus 6P device (and Galaxy S3), so I think the only time it ever works is when you first enable "device mode" because at that time, it's still somehow getting a click (I presume).

Chrome does not allow to grab the main frame scrollbar on Android (and thus in mobile emulation mode). skobes@, am I right here?

Unfortunately, to get full Android-like behavior with scrollbars, you have to reload after enabling mobile emulation. That's a limitation we were not able to get rid of.

@Comment 7

You are able to 'grab' the Android scrollbar if you first start to scroll. After it shows up, while it's there (for a few seconds), you can indeed grab it.

So I feel it should be allowed for custom ones as well, especially since all my content (in my case) is doing lasso selection (and thus, cannot pan). As such, for my mobile application, I am relying on the scrollbar.

Hmm, it seems to me that *no* scrollbars are draggable on real Android, but some scrollbars are draggable in mobile emulation mode.

I'm not sure if there was a product decision to make them undraggable, or if that's a bug.  Maybe aelias can shed some insight.

I think native Android scrollbars are too thin to work well as drag targets, but we could possibly make an exception for custom scrollbars.

Regardless, we should make mobile emulation mode match the real thing as much as possible.

skobes@ as per comment #7 this seems to be what it is doing. You need to reload to get the full android like behavior.

I'm guessing this issue can just be closed as working as intended?

Custom scrollbars are a webkit-prefixed misfeature I'd like us to eventually deprecate and remove anyway.  They don't provide any capabilities you can't achieve with normal HTML/CSS/JS, so the only valid use case for them from my POV is to remove the scrollbar entirely.

@10: Even after reloading, some scrollbars are draggable in mobile emulation mode.  But I guess that's tangential.

It sounds like Android scrollbars aren't meant to be draggable, and we don't want to add exceptions for custom scrollbars, so this bug is WontFix.