Link Swarming Tasklist and Botlist together

appengine/swarming/ui/res/imp/taskpage/task-page.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:
 
     <task-page>
 
@@ skipping 454 matching lines @@
                   <td>[[_humanDuration(_result.performance_stats.bot_overhead)]]</td>
                 </tr>
                 <tr>
                   <td>Downloading Inputs From Isolate</td>
                   <td>[[_humanDuration(_result.performance_stats.isolated_download.duration)]]</td>
                 </tr>
                 <tr>
                   <td>Uploading Outputs To Isolate</td>
                   <td>[[_humanDuration(_result.performance_stats.isolated_upload.duration)]]</td>
                 </tr>
-                <tr>
+                <tr hidden$="[[!_result.performance_stats.isolated_download.initial_size]]">
                   <td>Initial bot cache</td>
                   <td>[[_result.performance_stats.isolated_download.initial_number_items]] items;
                   [[_bytes(_result.performance_stats.isolated_download.initial_size)]]</td>
                 </tr>
               </table>
             </template>
 
             <div hidden$="[[_not(_task_exists)]]">
               <div class="title">Reproducing the task locally</div>
               <div class="reproduce">
@@ skipping 365 matching lines @@
         return result && result.state !== this.PENDING && result.state !== this.CANCELED && result.state != this.EXPIRED;
       },
 
       _wasNotPickedUp: function(result) {
         return result && !this._wasPickedUp(result);
       },
     });
   })();
   </script>
 </dom-module>