canvas: Change canvas to use JSContext instead of CanGc

[Narfinger]

This changes the methods in dom/canvas to use the new JSContext/&mut JSContext instead of CanGc.

Part of #40600

Signed-off-by: Narfinger Narfinger@users.noreply.github.com

Testing: This is a refactor, hence, compilation is the test.

[Narfinger]

I mostly did this to understand the JSContext changes coming up.
I have two questions, though (@sagudev or @jdm):

• I assume there is currently nothing for Constructor type methods?
• deserialize needs a method from GlobalScope to &mut JSContext. Does this currently exist?
• Is there anything else that I missed or did suboptimal?

[sagudev]

I assume there is currently nothing for Constructor type methods?

Yes, I need to fix codegen for them. I will do this tomorrow.

deserialize needs a method from GlobalScope to &mut JSContext. Does this currently exist?

I think deserialize actually needs to get cx passed as arg.

Is there anything else that I missed or did suboptimal?

I will check it tomorrow.

[sagudev]

I fixed codegen for constructor in f623081 and this PR looks alright.

I think we should defer ImageData changes to after we pass cx in serialize.

[Narfinger]

Ok done.
But I am still now quite sure how to handle the reflect_dom_object without can_gc.

[sagudev]

Ok done. But I am still now quite sure how to handle the reflect_dom_object without can_gc.

Ah, I need to write methods that will take &mut JSContext.