--- a/testing/marionette/action.js
+++ b/testing/marionette/action.js
@@ -4,17 +4,20 @@
 
 /* eslint no-dupe-keys:off */
 
 "use strict";
 
 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
 
 Cu.import("chrome://marionette/content/assert.js");
-Cu.import("chrome://marionette/content/element.js");
+const {
+  element,
+  WebElement,
+} = Cu.import("chrome://marionette/content/element.js", {});
 const {
   InvalidArgumentError,
   MoveTargetOutOfBoundsError,
   UnsupportedOperationError,
 } = Cu.import("chrome://marionette/content/error.js", {});
 Cu.import("chrome://marionette/content/event.js");
 const {pprint} = Cu.import("chrome://marionette/content/format.js", {});
 Cu.import("chrome://marionette/content/interaction.js");
@@ -357,17 +360,17 @@ action.PointerOrigin = {
 action.PointerOrigin.get = function(obj) {
   let origin = obj;
   if (typeof obj == "undefined") {
     origin = this.Viewport;
   } else if (typeof obj == "string") {
     let name = capitalize(obj);
     assert.in(name, this, pprint`Unknown pointer-move origin: ${obj}`);
     origin = this[name];
-  } else if (!element.isWebElementReference(obj)) {
+  } else if (!WebElement.isReference(obj)) {
     throw new InvalidArgumentError("Expected 'origin' to be a string or a " +
       pprint`web element reference, got ${obj}`);
   }
   return origin;
 };
 
 /** Represents possible subtypes for a pointer input source. */
 action.PointerType = {
@@ -1315,18 +1318,18 @@ function dispatchPointerMove(a, inputSta
   const timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
   // interval between pointermove increments in ms, based on common vsync
   const fps60 = 17;
 
   return new Promise(resolve => {
     const start = Date.now();
     const [startX, startY] = [inputState.x, inputState.y];
 
-    let target = action.computePointerDestination(a, inputState,
-        getElementCenter(a.origin, seenEls, window));
+    let coords = getElementCenter(a.origin);
+    let target = action.computePointerDestination(a, inputState, coords);
     const [targetX, targetY] = [target.x, target.y];
 
     if (!inViewPort(targetX, targetY, window)) {
       throw new MoveTargetOutOfBoundsError(
           `(${targetX}, ${targetY}) is out of bounds of viewport ` +
           `width (${window.innerWidth}) ` +
           `and height (${window.innerHeight})`);
     }
@@ -1425,17 +1428,14 @@ function capitalize(str) {
 
 function inViewPort(x, y, win) {
   assert.number(x, `Expected x to be finite number`);
   assert.number(y, `Expected y to be finite number`);
   // Viewport includes scrollbars if rendered.
   return !(x < 0 || y < 0 || x > win.innerWidth || y > win.innerHeight);
 }
 
-function getElementCenter(elementReference, seenEls, window) {
-  if (element.isWebElementReference(elementReference)) {
-    let uuid = elementReference[element.Key] ||
-        elementReference[element.LegacyKey];
-    let el = seenEls.get(uuid, window);
+function getElementCenter(el) {
+  if (element.isDOMElement(el)) {
     return element.coordinates(el);
   }
   return {};
 }

--- a/testing/marionette/element.js
+++ b/testing/marionette/element.js
@@ -658,31 +658,16 @@ element.isCollection = function(seq) {
 
 element.makeWebElement = function(uuid) {
   return {
     [element.Key]: uuid,
     [element.LegacyKey]: uuid,
   };
 };
 
-/**
- * Checks if |ref| has either |element.Key| or |element.LegacyKey|
- * as properties.
- *
- * @param {Object.<string, string>} ref
- *     Object that represents a web element reference.
- * @return {boolean}
- *     True if |ref| has either expected property.
- */
-element.isWebElementReference = function(ref) {
-  let properties = Object.getOwnPropertyNames(ref);
-  return properties.includes(element.Key) ||
-      properties.includes(element.LegacyKey);
-};
-
 element.generateUUID = function() {
   let uuid = uuidGen.generateUUID().toString();
   return uuid.substring(1, uuid.length - 1);
 };
 
 /**
  * Determines if <var>el</var> is stale.
  *

--- a/testing/marionette/test_element.js
+++ b/testing/marionette/test_element.js
@@ -209,27 +209,16 @@ add_test(function test_coordinates() {
   Assert.throws(() => element.coordinates(domEl, {}, {}));
   Assert.throws(() => element.coordinates(domEl, [], undefined));
   Assert.throws(() => element.coordinates(domEl, undefined, []));
   Assert.throws(() => element.coordinates(domEl, [], []));
 
   run_next_test();
 });
 
-add_test(function test_isWebElementReference() {
-  strictEqual(element.isWebElementReference({[element.Key]: "some_id"}), true);
-  strictEqual(element.isWebElementReference({[element.LegacyKey]: "some_id"}), true);
-  strictEqual(element.isWebElementReference(
-      {[element.LegacyKey]: "some_id", [element.Key]: "2"}), true);
-  strictEqual(element.isWebElementReference({}), false);
-  strictEqual(element.isWebElementReference({"key": "blah"}), false);
-
-  run_next_test();
-});
-
 add_test(function test_WebElement_ctor() {
   let el = new WebElement("foo");
   equal(el.uuid, "foo");
 
   for (let t of [42, true, [], {}, null, undefined]) {
     Assert.throws(() => new WebElement(t));
   }