[Devtools] Canvas network timeline experiment establishes scrolling

third_party/WebKit/Source/devtools/front_end/externs.js

Index: third_party/WebKit/Source/devtools/front_end/externs.js
diff --git a/third_party/WebKit/Source/devtools/front_end/externs.js b/third_party/WebKit/Source/devtools/front_end/externs.js
index 799ea010320f2fc86a1e3381ac92a114929e75a2..e7a94a56f8560e71614419804c66c8198e787bb4 100644
--- a/third_party/WebKit/Source/devtools/front_end/externs.js
+++ b/third_party/WebKit/Source/devtools/front_end/externs.js
@@ -624,6 +624,15 @@ ArrayBuffer.isView = function(obj) { }
  */
 Element.prototype.animate = function(keyframes, timing) { }
 
+/**
+ * @override
+ * @param {string} type
+ * @param {(!EventListener|!function (!Event): (boolean|undefined)|null)} listener
+ * @param {(boolean|!{capture: (boolean|undefined), once: (boolean|undefined), passive: (boolean|undefined)})=} options
+ * @this {EventTarget}
+ */
+Element.prototype.addEventListener = function(type, listener, options) { }
+
 var acorn = {
     /**
      * @param {string} text