2010-01-28 Rolf Bjarne Kvinge <RKvinge@novell.com>

2010-01-28  Rolf Bjarne Kvinge  <RKvinge@novell.com>

	* WebClient_2_1.cs: The async events must be invoked on a threadpool
	thread if the async method wasn't executed on the main thread, so save
	the synchronization context when the async method is called, and post
	the event to that synchronization context when done. This is also
	required when the async methods are executed on the main thread, since
	HttpWebRequest callbacks are now always executed on a threadpool thread.

svn path=/trunk/mcs/; revision=150370