Bug 1352572 - Add negative test for NPN_PostURLNotify(); r=bsmedberg

Note that this test never actually fails short of passing file parameter to
NPN_PostURLNotify actually causing the browser to crash. It can't distinguish
between the case when file is working or not.

MozReview-Commit-ID: 1G590ZWpHsE

--HG--
extra : rebase_source : c294bc109b893c81b6ee4c3114bb039eab77af08

dom/plugins/test/mochitest/test_streamNotify.html

@@ -85,6 +85,15 @@
                      }, null, true), "streamTest GET bad data: URI");
 
     ok(!p.postFileToURLTest("post.sjs"), "postFileToURLTest POST a file");
+
+    ok(!p.streamTest("post.sjs", true, "non-existent-file",
+                     function(r, t) {
+                       ok(false, "Shouldn't get write callback from file post");
+                     }, function(r, t) {
+                       ok(false, "Shouldn't get notify callback from file post");
+                     }, function(r, t) {
+                       ok(false, "Shouldn't get redirect callback from file post");
+                     }, true, true), "streamTest POST a file");
   }
   </script>