Add IDBDatabase.onversionchange

Author: japgolly

src/main/scala/org/scalajs/dom/raw/Idb.scala

@@ -622,6 +622,14 @@ class IDBDatabase extends EventTarget {
    */
   var onabort: js.Function1[Event, _] = js.native
 
+  /**
+    * The onversionchange event handler of the IDBDatabase interface handles the versionchange
+    * event, fired when a database structure change (IDBOpenDBRequest.onupgradeneeded event or
+    * IDBFactory.deleteDatabase) was requested elsewhere (most probably in another window/tab
+    * on the same computer).
+    */
+  var onversionchange: js.Function1[IDBVersionChangeEvent, _] = js.native
+
   /**
    * The method takes the name of the store as well as a parameter object. The parameter
    * object lets you define important optional properties. You can use the property to