Fix sorting of status to account for time bot has been dead.

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 319 matching lines @@
       },
       battery_voltage: function(){
         return "";
       },
       bot_temperature: function(bot){
         if (this._verbose) {
           return bot.state.temp.zones || UNKNOWN;
         }
         return bot.state.temp.average || UNKNOWN;
       },
+      cpu: function(bot) {
+        if (this._verbose) {
+          return this._attribute(bot, "cpu", "none").join(" | ");
+        }
+        return swarming.longest(this._attribute(bot, "cpu", "none"));
+      },
       device_temperature: function(){
         return "";
       },
       device_os: function(bot) {
         if (this._verbose) {
           return this._attribute(bot, "device_os", "none").join(" | ");
         }
         // This assumes that all devices hooked up to a bot are the same OS.
         return swarming.longest(this._attribute(bot, "device_os", "none"));
       },
@@ skipping 49 matching lines @@
         var u = this._state(bot, "running_time");
         if (!u) {
           return "unknown";
         }
         return sk.human.strDuration(u);
       },
       status: function(bot) {
         // If a bot is both dead and quarantined, show the deadness over the
         // quarentinedness.
         if (bot.is_dead) {
-          return "Dead.  Last seen " + sk.human.diffDate(bot.last_seen_ts) +
+          return "Dead. Last seen " + sk.human.diffDate(bot.last_seen_ts) +
               " ago";
         }
         if (bot.quarantined) {
           var msg = this._state(bot, "quarantined");
           if (msg) {
             msg = msg[0];
           };
           // Sometimes, the quarantined message is actually in "error".  This
           // happens when the bot code has thrown an exception.
           if (!msg || msg === "true" || msg === true) {
@@ skipping 141 matching lines @@
       last_seen: function(dir, botA, botB) {
         var botACol = botA.last_seen_ts;
         var botBCol = botB.last_seen_ts;
         return dir * naturalSort(botACol, botBCol)
       },
       running_time: function(dir, botA, botB) {
         var botACol = this._state(botA, "running_time") || 0;
         var botBCol = this._state(botB, "running_time") || 0;
         return dir * naturalSort(botACol, botBCol)
       },
+      status: function(dir, botA, botB) {
+        // Case 1: One of the bots is dead, sort dead bot over alive/quarantined bot.
+        if (botA.is_dead !== botB.is_dead) {
+          if (botA.is_dead) {
+            return dir;
+          } else {
+            return -dir;
+          }
+        }
+        // Case 2: Bots match on deadness, quarantinedness, or aliveness
+        // In this case, sort by last seen time.
+        if (botA.is_dead && botB.is_dead ||
+            botA.quarantined && botB.quarantined ||
+            !botA.is_dead && !botB.is_dead && !botA.quarantined && !botB.quarantined ) {
+          var botACol = botA.last_seen_ts;
+          var botBCol = botB.last_seen_ts;
+          return dir * naturalSort(botACol, botBCol)
+        }
+        // Case 3: One of the bots is quarantined.  Sort quarantined bot over alive bot.
+        if (botA.quarantined) {
+          return dir;
+        }
+        return -dir;
+      },
       uptime: function(dir, botA, botB) {
         var botACol = this._state(botA, "uptime") || 0;
         var botBCol = this._state(botB, "uptime") || 0;
         return dir * naturalSort(botACol, botBCol)
       },
     };
 
     Polymer({
       is: 'bot-list',
 
@@ skipping 128 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>