test: timers-ordering should be more precise

Internally we use hrtime to schedule when a timer will fire, to avoid
the perils of clock drift or other external operation making time go
backward. The timers ordering test should use the same timing mechanism

test/simple/test-timers-ordering.js

@@ -21,13 +21,15 @@
 
 var common = require('../common');
 var assert = require('assert');
+var Timer = process.binding('timer_wrap').Timer;
+
 var i;
 
 var N = 30;
 
 var last_i = 0;
 var last_ts = 0;
-var start = Date.now();
+var start = Timer.now();
 
 var f = function(i) {
   if (i <= N) {
@@ -36,7 +38,7 @@ var f = function(i) {
     last_i = i;
 
     // check that this iteration is fired at least 1ms later than the previous
-    var now = Date.now();
+    var now = Timer.now();
     console.log(i, now);
     assert(now >= last_ts + 1, 'current ts ' + now + ' < prev ts ' + last_ts + ' + 1');
     last_ts = now;