Add browser test for initial languages.

BUG=418573

Review URL: https://codereview.chromium.org/598023006

Cr-Commit-Position: refs/heads/master@{#303852}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 7c8d58e3..c229f67 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -165,6 +165,8 @@
       (
         r"^base[\\\/]process[\\\/]process_metrics_linux\.cc$",
         r"^chrome[\\\/]browser[\\\/]chromeos[\\\/]boot_times_loader\.cc$",
+        r"^chrome[\\\/]browser[\\\/]chromeos[\\\/]"
+            "customization_document_browsertest\.cc$",
         r"^components[\\\/]crash[\\\/]app[\\\/]breakpad_mac\.mm$",
         r"^content[\\\/]shell[\\\/]browser[\\\/]shell_browser_main\.cc$",
         r"^content[\\\/]shell[\\\/]browser[\\\/]shell_message_filter\.cc$",