debugCheckHasMaterial assert should just show the entire ancestor chain, one to a line

[jimbeveridge]

debugGetOwnershipChain takes a parameter indicating how many layers to dump. This means that every call site separately codes the dump depth, which is hard to modify.

It would be better if there were a global default value that could be set, then add an optional positional parameter to allow the caller to override the default if desired.

[Hixie]

The depth is intentionally different in different call sites. The call is quite expensive, and O(N). Call sites that happen a lot have to make it shorter to save time. Call sites that only trigger on error can give a much bigger number to aid debugging.

[jimbeveridge]

The use case I'm debugging is the lack of a Material widget. I need a depth much higher than 10 to figure it out.

[Hixie]

I discussed this with Jim and we concluded we should just have the assert show the entire ancestor chain, as a list, one to a line.