Autodisplay android_devices when appropriate

appengine/swarming/ui/res/imp/botlist/bot-list.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <bot-list>
 
@@ skipping 236 matching lines @@
     </swarming-app>
 
   </template>
   <script>
   (function(){
     var UNKNOWN = "unknown";
     // see dynamic-table for more information on specialColumns, headerMap,
     // columnMap, and specialSort
     var specialColumns = ["id", "task", "cloud_console_link", "mp_lease_id"];
 
+    var deviceColumns = ["battery_health", "battery_level", "battery_status", "battery_temperature", "battery_voltage", "device_temperature"];
+
     var headerMap = {
       // "id" and "task" are special, so they don't go here. They have their
       // headers hard-coded above.
       "android_devices": "Android Devices",
       "battery_health": "Battery Health",
       "battery_level": "Battery Level (%)",
       "battery_status": "Battery Status",
       "battery_temperature": "Battery Temp (°C)",
       "battery_voltage": "Battery Voltage (mV)",
       "bot_temperature": "Bot Temp (°C)",
@@ skipping 42 matching lines @@
       },
       bot_temperature: function(bot){
         if (this._verbose) {
           return bot.state.temp.zones || UNKNOWN;
         }
         return bot.state.temp.average || UNKNOWN;
       },
       device_temperature: function(){
         return "";
       },
+      device_os: function(bot) {
+        return this._attribute(bot, "device_os", "none").join(" | ");
+      },
       disk_space: function(bot) {
         var aliased = [];
         bot.disks.forEach(function(disk){
           var alias = sk.human.bytes(disk.mb, sk.MB);
           aliased.push(swarming.alias.apply(disk.mb, disk.id + " "+ alias));
         }.bind(this));
         if (this._verbose) {
           return aliased.join(" | ");
         }
         return aliased[0];
@@ skipping 252 matching lines @@
         _specialColumns: {
           type: Array,
           value: specialColumns,
         },
         _specialSort: {
           type: Object,
           value: specialSort,
         },
       },
 
-      observers:["_reload(_query_params,_auth_headers)"],
+      observers:[
+        "_reload(_query_params,_auth_headers)",
+        "_checkDeviceColumns(_columns.*)"
+      ],
 
       _androidAliasDevice: function(device) {
         if (device.notReady) {
           return UNAUTHENTICATED.toUpperCase();
         }
         return swarming.alias.android(this._deviceType(device));
       },
 
       _botClass: function(bot) {
         if (bot.is_dead) {
@@ skipping 14 matching lines @@
       },
 
       _ccText: function(bot){
         var z = this._attribute(bot, "zone")[0];
         if (z === "unknown") {
           return "Not on GCE";
         }
         return "View Bot";
       },
 
+      _checkDeviceColumns: function() {
+        var shouldAdd = false;
+        for (var i = 0; i< this._columns.length; i++) {
+          var col = this._columns[i];
+          if (col === "android_devices") {
+            return;
+          }
+          if (deviceColumns.indexOf(col) !== -1) {
+            shouldAdd = true;
+          }
+        }
+        if (shouldAdd) {
+          this.push("_columns", "android_devices");
+          sk.errorMessage("Some of the columns selected require 'android_devices' to be displayed.  It has been automatically added.", 4000);
+        }
+      },
+
       _deviceColumn: function(col, device) {
         var f = deviceColumnMap[col];
         if (!f || !device) {
           return "";
         }
         return f.bind(this)(device);
       },
 
       _deviceClass: function(device) {
         if (!device.okay) {
@@ skipping 14 matching lines @@
           return;
         }
         var url = "/api/swarming/v1/bots/list?" + sk.query.fromParamSet(this._query_params);
         this.$.page_bots.load(url,this._auth_headers);
       }
 
     });
   })();
   </script>
 </dom-module>