onDetachedFromWindow is called before onAttachedToWindow

Multiple threads are adding messages about the current
state of the views to the main looper. This can cause
onDetachedFromWindow to be posted on the looper before
onAttachedToWindow. This change will make sure to only
dispatch onDetachedFromWindow if we have previously
dispatched onAttachToWindow.

Change-Id: Ibc7cbcafb098bc000d2ef5480d2110d3fff4d55a