Ignore blank origins in the Security panel.

Source/devtools/front_end/sdk/NetworkManager.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 344 matching lines @@
 
         this._dispatchResponseReceivedSecurityDetails(requestId, response);
     },
 
     /**
      * @param {!NetworkAgent.RequestId} requestId
      * @param {!NetworkAgent.Response} response
      */
     _dispatchResponseReceivedSecurityDetails: function(requestId, response)
     {
+        var origin = WebInspector.ParsedURL.splitURLIntoPathComponents(response.url)[0];

[dgozman, 2015/09/03 21:01:16]

Side note: do you need to include port here? If so, there is ParsedURL.domain()
function.

+        if (!origin) {
+            // We don't handle resources like data: URIs. Most of them don't affect the lock icon.
+            return;
+        }
+
         var eventData = {};
         eventData.requestId = requestId;
-        eventData.origin = WebInspector.ParsedURL.splitURLIntoPathComponents(response.url)[0];
+        eventData.origin = origin;
         eventData.securityState = response.securityState;
         if (response.securityDetails) {
             /**
              * @this {WebInspector.NetworkDispatcher}
              * @param {?Protocol.Error} error
              * @param {!NetworkAgent.CertificateDetails} certificateDetails
              */
             function callback(error, certificateDetails)
             {
                 if (error)
@@ skipping 385 matching lines @@
             target.networkAgent().removeBlockedURL(url);
     },
 
     __proto__: WebInspector.Object.prototype
 }
 
 /**
  * @type {!WebInspector.MultitargetNetworkManager}
  */
 WebInspector.multitargetNetworkManager;