Add Device errors to bot-list status

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 386 matching lines @@
           return "Dead.  Last seen " + sk.human.diffDate(bot.last_seen_ts) +
               " ago";
         }
         if (bot.quarantined) {
           var msg = this._state(bot, "quarantined")[0];
           // Sometimes, the quarantined message is actually in "error".  This
           // happens when the bot code has thrown an exception.
           if (msg === UNKNOWN || msg === "true" || msg === true) {
             msg = this._attribute(bot, "error");
           }
+          if (msg === "No available devices.") {

[stephana, 2017/03/21 17:33:39]

This seems very fragile. Is there no stricter way (via field that has a fixed
set of values) to determine whether we need to look at other fields. 

[kjlubick, 2017/03/21 19:56:15]

Removed the if statement, because I think it will always be useful to see the
device errors.

+            var errs = [];
+            // Show all the errors that are active to make it more clear if this
+            // is a transient error (e.g. device is too hot) or if it is requires
+            // human interaction (e.g. device is unauthorized)
+            this._devices(bot).forEach(function(d){
+              if (d.state !== "available") {
+                errs.push(d.state);
+              }
+            });
+            if (errs.length) {
+              msg += " ["+errs.join(",")+"]";
+            }
+          }
           return "Quarantined: " + msg;
         }
         return "Alive";
       },
       task: function(bot) {
         return this._taskId(bot);
       },
       uptime: function(bot) {
         var u = this._state(bot, "uptime");
         if (!u) {
@@ skipping 270 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>