Land patch from issue 854603005 at patchset 1 (http://crrev.com/854603005#ps1)
on behalf of qsr@

TBR=qsr@chromium.org

Review URL: https://codereview.chromium.org/852983003
diff --git a/BUILD.gn b/BUILD.gn
index 86839fa..d9413fd 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//testing/test.gni")
+
 pdf_use_skia = false
 
 config("pdfium_config") {