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

third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt

Index: third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt
diff --git a/third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt b/third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt
index 21f62d3b2c971585336e09afd5f954f7156969d1..e7ba8c4d60a5e4a37291138d4bd2e010c650a8f4 100644
--- a/third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt
+++ b/third_party/WebKit/LayoutTests/inspector/elements/event-listener-sidebar-jquery2-expected.txt
@@ -7,26 +7,31 @@ Inspect Me
 [expanded] button#nodeRemoveevent-listener-sidebar-jquery2.html:11
     useCapture: true
     passive: false
+    once: false
     handler: function (){ console.log("second jquery"); }
 == frameworkUser
 [expanded] button#nodeRemoveevent-listener-sidebar-jquery2.html:10
     useCapture: true
     passive: false
+    once: false
     handler: function (){ console.log("first jquery"); }
 == normal
 [expanded] button#nodeRemoveevent-listener-sidebar-jquery2.html:13
     useCapture: false
     passive: false
+    once: false
     handler: function () { console.log("onclick"); }
 == normal
 [expanded] button#nodeRemoveevent-listener-sidebar-jquery2.html:12
     useCapture: false
     passive: false
+    once: false
     handler: function () { console.log("addEventListener"); }
 == frameworkInternal
 [expanded] button#nodeRemovejquery-2.1.4.min.js:3
     useCapture: false
     passive: false
+    once: false
     handler: function (b){return typeof n!==U&&n.event.triggered!==b.type?n.event.dispatch.apply(a,arguments):void 0}
 
 ======== load ========
@@ -34,6 +39,7 @@ Inspect Me
 [expanded] WindowRemoveevent-listener-sidebar-jquery2.html:52
     useCapture: false
     passive: false
+    once: false
     handler: function onload(event) {
   onloadHandler()
 }