Make waitFor check predicate before logging slowness.

content/test/data/media/mediarecorder_test_utils.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 // This function will be used only when we need to wait for data gathering.
 function waitDuration(duration) {
   return new Promise(function(resolve, reject) {
     console.log('Waiting for ', duration.toString(), 'msec');
     setTimeout(
         function() {
           console.log('Done waiting');
           resolve();
         }, duration);
   });
 }
 
 function waitFor(description, predicate) {
   return new Promise(function(resolve, reject) {
     var startTime = new Date();
     console.log('Waiting for', description.toString());
     var check = setInterval(function() {
       var elapsed = new Date() - startTime;
-      if (elapsed > 3000) {
+      if (predicate()) {
+        clearInterval(check);
+        resolve();
+      } else if (elapsed > 3000) {
         startTime = new Date();
         console.log('Still waiting for satisfaction of ' +
             predicate.toString());
-      } else if (predicate()) {
-        clearInterval(check);
-        resolve();
       }
     }, 50);
   });
 }