Return an error for LoadIconImage() for BeOS because netlib is running in the UI thread. Thanks to Duncan Wilcox (duncan@be.com) for this fix.

gfx/src/nsDeviceContext.cpp

@@ -346,7 +346,7 @@ NS_IMETHODIMP DeviceContextImpl::LoadIconImage(PRInt32 aId, nsIImage*& aImage)
 {
   // XXX synchronous image loading doesn't work on unix or mac yet
   // because netlib is not in its own thread.
-#if defined(XP_UNIX) || defined(XP_MAC)
+#if defined(XP_UNIX) || defined(XP_MAC) || defined(XP_BEOS)
   return NS_ERROR_FAILURE;
 #endif
   nsresult  result;