core-list-dart x coords on the row css transform incorrect when adding or removing items from the list #206
Description
See https://groups.google.com/a/dartlang.org/forum/m/#!topic/web/UIkUq7Fb9-Y
When I remove items or add items to / from core-list the x coordinate becomes wrong. Either it is offset in a +ve x direction (when removing items) causing the list to appear lower in the page. Or -ve (when adding items) causing them to disappear entirely
Moving items in the list (a single remove + insert in the same observe cycle) works fine.
For example is an example taken from the chrome dev tools inspect element
transform: translate3d(0px, -1290px, 0px)
Note I have eliminated scrollTarget as being a potential cause.
Note this used to work until recently. I have had this basic code in place and use it often myself. I have only now noticed this for the first time. So I suspect some recent change