Import hr-time and user-timing tests, remove redundant webperf copies

LayoutTests/imported/web-platform-tests/user-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
  */
 
 //
@@ skipping 134 matching lines @@
 
 function test_greater_or_equals(value, greater_than, msg, properties)
 {
     wp_test(function () { assert_true(value >= greater_than, msg); }, msg, properties);
 }
 
 function test_not_equals(value, notequals, msg, properties)
 {
     wp_test(function() { assert_true(value !== notequals, msg); }, msg, properties);
 }