Add {{streamlen}} macro to javascript tests.

Change-Id: I7c9858ba602162049cabc61c78fc09e9006dfa47
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/59716
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

testing/resources/javascript/xfa_specific/bug_985781.in

diff --git a/testing/resources/javascript/xfa_specific/bug_985781.in b/testing/resources/javascript/xfa_specific/bug_985781.in
index 1390d35..2b20d33 100644
--- a/testing/resources/javascript/xfa_specific/bug_985781.in
+++ b/testing/resources/javascript/xfa_specific/bug_985781.in
@@ -4,6 +4,7 @@
 {{include ../../xfa_preamble_3_0.fragment}}
 {{include ../../xfa_config_4_0.fragment}}
 {{object 5 0}} <<
+  {{streamlen}}
 >>
 stream
 <template>