Refactor post requests, implement bot cancel/terminate

appengine/swarming/elements/res/imp/common/common-behavior.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.
 
   It contains the definition of the following Behaviors:
 
     SwarmingBehaviors.CommonBehavior
 
   To use it, include
@@ skipping 50 matching lines @@
       },
 
       _or: function() {
         var result = false;
         // can't use .foreach, as arguments isn't really an Array.
         for (var i = 0; i < arguments.length; i++) {
           result = result || arguments[i];
         }
         return result;
       },
+
+      // _postWithToast makes a post request and updates the provided paper-toast
+      // element with the response, regardless of failure.
+      _postWithToast: function(url, msg, auth_headers) {

[jcgregorio, 2016/09/06 20:40:56]

Now that you are using errorMessage and the error-toast is a separate element,
this doesn't need to be part of a behavior, it can go into the swarming JS.

[kjlubick, 2016/09/07 12:00:20]

Done.

+        // Keep toast displayed until we hear back from the request.
+        sk.errorMessage(msg, 0);
+
+        sk.request("POST", url, undefined, auth_headers).then(function(response) {
+          sk.errorMessage("Request sent.  Response: "+response, 3000);
+        }.bind(this)).catch(function(reason) {
+          console.log("Request failed", reason);
+          sk.errorMessage("Request failed.  Reason: "+reason, 5000);
+        }.bind(this));
+      }
     };
   })();
 </script>