--- a/content/media/gtest/TestWebMBuffered.cpp
+++ b/content/media/gtest/TestWebMBuffered.cpp
@@ -1,13 +1,14 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "gtest/gtest.h"
+#include "mozilla/ArrayUtils.h"
 #include <stdio.h>
 #include "nsTArray.h"
 #include "WebMBufferedParser.h"
 
 using namespace mozilla;
 
 // "test.webm" contains 8 SimpleBlocks in a single Cluster with the following attributes
 static const uint64_t gTimecodes[] = { 66000000, 160000000, 100000000, 133000000,