Chip not cleaning up its MutationObserver when disconnected

[jcfranco]

Check existing issues

• I have checked for existing issues to avoid duplicates

Actual Behavior

Memory leak when adding/removing chips.

via @ycabon

Expected Behavior

Chips properly clean up after being removed from the DOM.

Reproduction Sample

https://codepen.io/jcfranco/pen/JjexPVj

Reproduction Steps

1. open devtools memory tab
2. click "add chip" then "remove chip" to warm up all the statics and what not
3. take a memory snapshot
4. click "add chip" then "remove chip"
5. take another snapshot
6. compare snapshot 2 with 1

Reproduction Version

1.4.3

Relevant Info

No response

Regression?

No response

Priority impact

p1 - need for current milestone

Impact

No response

Calcite package

• @esri/calcite-components
• @esri/calcite-components-react

Esri team

ArcGIS Maps SDK for JavaScript

[jcfranco]

Even though the observer is properly cleaned up on removal, I think there's something else going on that could be causing a memory leak (possibly w/ Stencil). Even adding and removing a very simple component yields a bump in memory.