Bug 474472. reftest harness should go back to the event loop after reftest-wait is removed and before we start checking isMozAfterPaintPending, in case reftest-wait was removed in a load event handler and that load event will unsuppress painting after the event handler has run. r=dbaron

--HG--
extra : rebase_source : 8b75034df21cf20db0160fa13e807225b45171b6

layout/tools/reftest/reftest.js

@@ -623,6 +623,14 @@ function OnDocumentLoad(event)
 
             // We don't want to be notified again
             contentRootElement.removeEventListener("DOMAttrModified", AttrModifiedListener, false);
+            // Wait for the next return-to-event-loop before continuing to flush rendering and
+            // check isMozAfterPaintPending --- for example, the attribute may have been modified
+            // in an subdocument's load event handler, in which case we need load event processing
+            // to complete and unsuppress painting before we check isMozAfterPaintPending.
+            setTimeout(AttrModifiedListenerContinuation, 0);
+        }
+
+        function AttrModifiedListenerContinuation() {
             if (doPrintMode())
                 setupPrintMode();
             FlushRendering();