Bug 1587233 [wpt PR 19587] - [2dcontext] Include required resource, a=testonly

Automatic update from web-platform-tests
[2dcontext] Include required resource (#19587)

"common.sub.js" references a function named `getVideoURI` at the top
level. This function is provided by "/common/media.js"; if the latter
file is not included, "common.sub.js" cannot be executed.

Load the required resource prior to "common.sub.js" so that the test may
run to completion.
--

wpt-commits: 72fcf2b027ede6465ee5ad9edbab8c8b8bd8c888
wpt-pr: 19587

testing/web-platform/tests/2dcontext/imagebitmap/createImageBitmap-serializable.html

@@ -4,6 +4,7 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="/common/namespaces.js"></script>
+<script src="/common/media.js"></script>
 <script src="common.sub.js"></script>
 <div id=log></div>
 <script>