Enable ServerTiming support

third_party/WebKit/LayoutTests/external/wpt/server-timing/resources/webperftestharness.js

+/*
+Distributed under both the W3C Test Suite License [1] and the W3C
+3-clause BSD License [2]. To contribute to a W3C Test Suite, see the
+policies and contribution forms [3].
+
+[1] http://www.w3.org/Consortium/Legal/2008/04-testsuite-license
+[2] http://www.w3.org/Consortium/Legal/2008/03-bsd-license
+[3] http://www.w3.org/2004/10/27-testcases
+ */
+
+// assert for every entry in `expectedEntries`, there is a matching entry _somewhere_ in `actualEntries`
+function test_entries(actualEntries, expectedEntries) {

[panicker, 2017/04/14 19:31:04]

why not move this to the common util?
(There is nothing specific to server-timing here)

+  test_equals(actualEntries.length, expectedEntries.length)
+  expectedEntries.forEach(function (expectedEntry) {
+    test_true(!!actualEntries.find(function (actualEntry) {
+      return typeof Object.keys(expectedEntry).find(function (key) {
+            return actualEntry[key] !== expectedEntry[key]
+          }) === 'undefined'
+    }))
+  })
+}