Bug 1284763 - Request longer timeout for test_anchor_area_referrer.html; r=jmaher

This test runs 276 seconds on average on Android Debug; when it takes longer
than 300 seconds, the test times out, producing intermittent failures.

dom/base/test/test_anchor_area_referrer.html

@@ -14,6 +14,8 @@
 
   <script type="application/javascript">
 
+  SimpleTest.requestLongerTimeout(2);
+
   const SJS = "://example.com/tests/dom/base/test/referrer_testserver.sjs?";
   const PARAMS = ["ATTRIBUTE_POLICY", "NEW_ATTRIBUTE_POLICY", "META_POLICY", "REL", "SCHEME_FROM", "SCHEME_TO"];