Backed out changeset 770edab72eb0 (bug 1620324) for XPCshell failures. CLOSED TREE

accessible/mac/MOXWebAreaAccessible.mm

@@ -128,6 +128,8 @@ using namespace mozilla::a11y;
   } else {
     mStartElem = root;
   }
+  MOZ_ASSERT(!mStartElem.IsNull(),
+             "Performing search with null gecko accessible!");
 
   mWebArea = root;