iron-resize event does not correctly scroll to currently selected item

[shawncplus]

Description

paper-tabs inside a paper-toolbar inside a paper-header-panel. On load the tabs are hidden but have a default selected value (which happens to be the last and currently off-screen tab). On finishing load the paper-tabs are shown and I explicitly fire iron-resize on the paper-tabs element to force render of the scrollable arrows if necessary.

Expected outcome

iron-resize event and the subsequent call to _tabChanged() inside the _onResize() call should scroll to the currently selected item

Actual outcome

Does not scroll to the currently selected item

Live Demo

Reproduction JSBin: https://jsbin.com/fokuvo/edit?html,output

Resize your screen to about iphone size (375 width) to see the tab scrolly-ness

Possible fix

In userspace see my workaround (explicitly firing, iron-select as well as iron-resize), if it were to be fixed inside paper-tabs it looks like the fix is to simply pass the currently selected item as the "old" item in _onResize() i.e., _tabChanged(this.selectedItem, this.selectedItem);

Browsers Affected

• Chrome
• Firefox
• Safari 9
• Safari 8
• Safari 7
• Edge
• IE 11
• IE 10

[pomber]

When should paper-tabs scroll to the selected tab?
I'm having a similar issue when having several tabs and the last one is selected declaratively.
Here is a demo: https://jsbin.com/ciqasuhici/2/edit?html,output