Optimize GetVisualTreeElementsWindowsInternal

[symbiogenesis]

There were multiple enumerations occurring in the Windows implementation of GetVisualTreeElements.

Using a HashSet, in particular, for the Contains() check within the other enumeration should especially help speed things up. And adding everything in reverse order in a single enumeration.

[ghost]

Hey there @symbiogenesis! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[mattleibow]

Is it possible to add a benchmark for this? In particular, the allocations may be interesting - or maybe no.

[mattleibow]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[symbiogenesis]

Benchmarks for latest version that just uses a for loop:

Before:

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
GetVisualTreeElements	134.6 ms	2.64 ms	2.60 ms	6750.0000	2000.0000	250.0000	58.46 MB

After:

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
GetVisualTreeElements	123.2 ms	2.32 ms	2.27 ms	6800.0000	1800.0000	400.0000	58.46 MB

[jonathanpeppers]

Ok, the new code does look much better (performance-wise) to me!

I'll lean on the MAUI team's knowledge, if we have enough tests to know this doesn't break anything.

[symbiogenesis]

Maybe retry the failed jobs?