Add once field to devtools so it can be queried by lighthouse.

third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js

 /*
  * Copyright (C) 2009 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 533 matching lines @@
         }
         fulfill(payloads.map(createEventListener.bind(this)));
       }
 
       /**
        * @this {WebInspector.RemoteObjectImpl}
        * @param {!Protocol.DOMDebugger.EventListener} payload
        */
       function createEventListener(payload) {
         return new WebInspector.EventListener(
-            this._target, this, payload.type, payload.useCapture, payload.passive,
+            this._target, this, payload.type, payload.useCapture, payload.passive, payload.once,
             payload.handler ? this.target().runtimeModel.createRemoteObject(payload.handler) : null,
             payload.originalHandler ? this.target().runtimeModel.createRemoteObject(payload.originalHandler) : null,
             /** @type {!WebInspector.DebuggerModel.Location} */ (this._debuggerModel.createRawLocationByScriptId(
                 payload.scriptId, payload.lineNumber, payload.columnNumber)),
             payload.removeFunction ? this.target().runtimeModel.createRemoteObject(payload.removeFunction) : null);
       }
     }
   }
 
   /**
@@ skipping 850 matching lines @@
     }
   }
 
   /**
    * @return {!WebInspector.RemoteObject}
    */
   object() {
     return this._object;
   }
 };