Fixes Bug 305783 - dragging a file over a directory #c4

     does not expand the dir => Bug discovered: When you drag a
     item onto a folder-view-item and then move it away
     instantly before the autoactivation event is triggered
     (After 750ms), the folder will be opened anyway.

BUG: 305783
REVIEW: 106381
FIXED-IN: 4.9.2
(cherry picked from commit 9ab8bcd6)