Expose RTT and downlink bandwidth using experimental Javascript API

third_party/WebKit/Source/modules/netinfo/NetworkInformation.idl

 // Copyright 2014 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.
 
 // https://wicg.github.io/netinfo/#the-networkinformation-interface
 
 enum ConnectionType {
     "cellular",
     "bluetooth",
     "ethernet",
     "wifi",
     "wimax",
     "other",
     "none",
     "unknown"
 };
 
 typedef unrestricted double Megabit;
 
 [
     ActiveScriptWrappable,
     DependentLifetime,
     Exposed=(Window,Worker),
     RuntimeEnabled=NetworkInformation,
 ] interface NetworkInformation : EventTarget {
     [MeasureAs=NetInfoType] readonly attribute ConnectionType type;
     [RuntimeEnabled=NetInfoDownlinkMax, MeasureAs=NetInfoDownlinkMax] readonly attribute Megabit downlinkMax;
     [RuntimeEnabled=NetInfoDownlinkMax, MeasureAs=NetInfoOnChange] attribute EventHandler onchange;
     [MeasureAs=NetInfoOnTypeChange] attribute EventHandler ontypechange;
+    [RuntimeEnabled=NetInfoRtt, MeasureAs=NetInfoRtt] readonly attribute  unsigned long long rtt;
+    [RuntimeEnabled=NetInfoDownlink, MeasureAs=NetInfoDownlink] readonly attribute Megabit downlink;
 };