--- a/devtools/server/actors/inspector/document-walker.js
+++ b/devtools/server/actors/inspector/document-walker.js
@@ -15,30 +15,33 @@ const SKIP_TO_PARENT = "SKIP_TO_PARENT";
 const SKIP_TO_SIBLING = "SKIP_TO_SIBLING";
 
 /**
  * Wrapper for inDeepTreeWalker.  Adds filtering to the traversal methods.
  * See inDeepTreeWalker for more information about the methods.
  *
  * @param {DOMNode} node
  * @param {Window} rootWin
- * @param {Number} whatToShow
- *        See nodeFilterConstants / inIDeepTreeWalker for options.
- * @param {Function} filter
- *        A custom filter function Taking in a DOMNode and returning an Int. See
- *        WalkerActor.nodeFilter for an example.
- * @param {String} skipTo
- *        Either SKIP_TO_PARENT or SKIP_TO_SIBLING. If the provided node is not compatible
- *        with the filter function for this walker, try to find a compatible one either
- *        in the parents or in the siblings of the node.
+ * @param {Object}
+ *        - {Number} whatToShow
+ *          See nodeFilterConstants / inIDeepTreeWalker for options.
+ *        - {Function} filter
+ *          A custom filter function Taking in a DOMNode and returning an Int. See
+ *          WalkerActor.nodeFilter for an example.
+ *        - {String} skipTo
+ *          Either SKIP_TO_PARENT or SKIP_TO_SIBLING. If the provided node is not
+ *          compatible with the filter function for this walker, try to find a compatible
+ *          one either in the parents or in the siblings of the node.
  */
 function DocumentWalker(node, rootWin,
-  whatToShow = nodeFilterConstants.SHOW_ALL,
-  filter = standardTreeWalkerFilter,
-  skipTo = SKIP_TO_PARENT) {
+  {
+    whatToShow = nodeFilterConstants.SHOW_ALL,
+    filter = standardTreeWalkerFilter,
+    skipTo = SKIP_TO_PARENT
+  } = {}) {
   if (Cu.isDeadWrapper(rootWin) || !rootWin.location) {
     throw new Error("Got an invalid root window in DocumentWalker");
   }
 
   this.walker = Cc["@mozilla.org/inspector/deep-tree-walker;1"]
     .createInstance(Ci.inIDeepTreeWalker);
   this.walker.showAnonymousContent = true;
   this.walker.showSubDocuments = true;

--- a/devtools/server/actors/inspector/walker.js
+++ b/devtools/server/actors/inspector/walker.js
@@ -194,20 +194,20 @@ var WalkerActor = protocol.ActorClassWit
   },
 
   toString: function() {
     return "[WalkerActor " + this.actorID + "]";
   },
 
   getDocumentWalker: function(node, whatToShow, skipTo) {
     // Allow native anon content (like <video> controls) if preffed on
-    let nodeFilter = this.showAllAnonymousContent
+    let filter = this.showAllAnonymousContent
                     ? allAnonymousContentTreeWalkerFilter
                     : standardTreeWalkerFilter;
-    return new DocumentWalker(node, this.rootWin, whatToShow, nodeFilter, skipTo);
+    return new DocumentWalker(node, this.rootWin, {whatToShow, filter, skipTo});
   },
 
   destroy: function() {
     if (this._destroyed) {
       return;
     }
     this._destroyed = true;
     protocol.Actor.prototype.destroy.call(this);

--- a/devtools/server/tests/mochitest/test_inspector-anonymous.html
+++ b/devtools/server/tests/mochitest/test_inspector-anonymous.html
@@ -75,19 +75,21 @@ window.onload = function() {
 
   addAsyncTest(async function testNativeAnonymousStartingNode() {
     info("Tests attaching an element that a walker can't see.");
 
     let serverWalker = DebuggerServer.searchAllConnectionsForActor(gWalker.actorID);
     let docwalker = new _documentWalker(
       gInspectee.querySelector("select"),
       gInspectee.defaultView,
-      nodeFilterConstants.SHOW_ALL,
-      () => {
-        return nodeFilterConstants.FILTER_ACCEPT;
+      {
+        whatToShow: nodeFilterConstants.SHOW_ALL,
+        filter: () => {
+          return nodeFilterConstants.FILTER_ACCEPT;
+        }
       }
     );
     let scrollbar = docwalker.lastChild();
     is(scrollbar.tagName, "scrollbar", "An anonymous child has been fetched");
 
     let node = await serverWalker.attachElement(scrollbar);
 
     ok(node, "A response has arrived");