[CrOS Tether] Add tether settings section to the MD settings page.

chrome/browser/resources/settings/internet_page/network_summary.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.
 
 /**
  * @fileoverview Polymer element for displaying a summary of network states
  * by type: Ethernet, WiFi, Cellular, WiMAX, and VPN.
  */
 
 /** @typedef {chrome.networkingPrivate.DeviceStateProperties} */
@@ skipping 268 matching lines @@
       newDeviceStates = Object.assign({}, this.deviceStates);
     }
 
     // Clear any current networks.
     var activeNetworkStatesByType =
         /** @type {!Map<string, !CrOnc.NetworkStateProperties>} */ (new Map);
 
     // Complete list of states by type.
     /** @type {!NetworkStateListObject} */ var newNetworkStateLists = {
       Ethernet: [],
+      Tether: [],
       WiFi: [],
       Cellular: [],
       WiMAX: [],
       VPN: [],
     };
 
     var firstConnectedNetwork = null;
     networkStates.forEach(function(networkState) {
       var type = networkState.Type;
       if (!activeNetworkStatesByType.has(type)) {
         activeNetworkStatesByType.set(type, networkState);
         if (!firstConnectedNetwork && networkState.Type != CrOnc.Type.VPN &&
             networkState.ConnectionState == CrOnc.ConnectionState.CONNECTED) {
           firstConnectedNetwork = networkState;
         }
       }
-      if (newNetworkStateLists.hasOwnProperty(type)) {
-        newNetworkStateLists[type].push(networkState);
-      }
+      newNetworkStateLists[type].push(networkState);
     }, this);
 
     this.defaultNetwork = firstConnectedNetwork;
 
     // Create a VPN entry in deviceStates if there are any VPN networks.
     if (newNetworkStateLists.VPN && newNetworkStateLists.VPN.length > 0) {
       newDeviceStates.VPN = /** @type {DeviceStateProperties} */ ({
         Type: CrOnc.Type.VPN,
         State: chrome.networkingPrivate.DeviceStateType.ENABLED
       });
     }
 
     // Push the active networks onto newActiveNetworkStates in order based on
     // device priority, creating an empty state for devices with no networks.
     var newActiveNetworkStates = [];
     this.activeNetworkIds_ = new Set;
     var orderedDeviceTypes = [
-      CrOnc.Type.ETHERNET, CrOnc.Type.WI_FI, CrOnc.Type.CELLULAR,
-      CrOnc.Type.WI_MAX, CrOnc.Type.VPN
+      CrOnc.Type.ETHERNET, CrOnc.Type.TETHER, CrOnc.Type.WI_FI,

[stevenjb, 2017/04/26 17:05:08]

Let's place TETHER after CELLULAR for now.

[Kyle Horimoto, 2017/04/26 17:17:41]

Done.

+      CrOnc.Type.CELLULAR, CrOnc.Type.WI_MAX, CrOnc.Type.VPN
     ];
     for (var i = 0; i < orderedDeviceTypes.length; ++i) {
       var type = orderedDeviceTypes[i];
       var device = newDeviceStates[type];
       if (!device)
         continue;
       var state = activeNetworkStatesByType.get(type) || {GUID: '', Type: type};
       if (state.Source === undefined &&
           device.State == chrome.networkingPrivate.DeviceStateType.PROHIBITED) {
         // Prohibited technologies are enforced by the device policy.
         state.Source = CrOnc.Source.DEVICE_POLICY;
       }
       newActiveNetworkStates.push(state);
       this.activeNetworkIds_.add(state.GUID);
     }
 
     this.deviceStates = newDeviceStates;
     this.networkStateLists_ = newNetworkStateLists;
     // Set activeNetworkStates last to rebuild the dom-repeat.
     this.activeNetworkStates_ = newActiveNetworkStates;
   },
 });