ComboBox (<disco-combo-box>)
A Metro-style combo box for picking from a short list of options.

Usage
<disco-combo-box>
<disco-combo-box-item value="1">Visual Studio 2013</disco-combo-box-item>
<disco-combo-box-item value="2" selected>Silverlight 8.1</disco-combo-box-item>
<disco-combo-box-item value="3">Windows Runtime</disco-combo-box-item>
<disco-combo-box-item value="4">XAML Debugger</disco-combo-box-item>
</disco-combo-box>
Attributes
open: Whether the combo box is expanded.value: The selected value (mirrors the selected item).
Properties
selectedIndex(number): Selected item index.value(string): Selected item value.
Events
change: Fired when the selection changes.event.detailincludesindex,value, anditem.
Child Components
<disco-combo-box-item>
value: Value string for the option.selected: Marks the item as initially selected.