Add test for bug 620428 (setinterval cancellation)

testing/resources/bug_620428.pdf

Index: testing/resources/bug_620428.pdf
diff --git a/testing/resources/bug_551248.pdf b/testing/resources/bug_620428.pdf
similarity index 88%
copy from testing/resources/bug_551248.pdf
copy to testing/resources/bug_620428.pdf
index cca1872ee7679be24520da251703bd62784af1c2..ff625b7a2e387d4a2d67b1b14a2667bc18466075 100644
--- a/testing/resources/bug_551248.pdf
+++ b/testing/resources/bug_620428.pdf
@@ -66,11 +66,16 @@ endobj
 50 0 obj <<
 >>
 stream
-function startDelay()
-{
+function fireTimeOut() {
   app.alert("hello world");
 }
-app.setTimeOut("startDelay()", 3000);
+function fireInterval() {
+  app.alert("goodbye world");
+}
+var timer = app.setTimeOut("fireTimeOut()", 3000);
+var interval = app.setInterval("fireInterval()", 1000);
+app.clearTimeOut(timer);
+app.clearInterval(interval);
 endstream
 endobj
 xref
@@ -130,5 +135,5 @@ trailer <<
   /Root 1 0 R
 >>
 startxref
-954
+1135
 %%EOF