Add missing endobj keywords to test files.

Change-Id: I223daeace6b2c89c1b250909f66c595c6eb5f7b6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/66212
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

testing/resources/javascript/bug_959274_1.in

diff --git a/testing/resources/javascript/bug_959274_1.in b/testing/resources/javascript/bug_959274_1.in
index 74909c0..9efb9dc 100644
--- a/testing/resources/javascript/bug_959274_1.in
+++ b/testing/resources/javascript/bug_959274_1.in
@@ -23,6 +23,7 @@
   /Contents [21 0 R]
   /MediaBox [0 0 612 792]
 >>
+endobj
 % OpenAction action
 {{object 10 0}} <<
   /Type /Action