Add back deprecated Polymer.Gestures.add and Polymer.Gestures.remove

Add tests

Fixes #3936

src/utils/gestures.html

@@ -723,7 +723,10 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
   gestures.findOriginalTarget = gestures._findOriginalTarget;
 
   /** @deprecated */
-  gestures.add = gestures._add;
+  gestures.add = gestures.addListener;
+
+  /** @deprecated */
+  gestures.remove = gestures.removeListener;
 
   Polymer.Gestures = gestures;
 

test/unit/gestures-elements.html

@@ -203,3 +203,12 @@ var EventCaptureBehavior = {
     });
   </script>
 </dom-module>
+
+<dom-module id="x-imperative">
+  <script>
+  Polymer({
+    is: 'x-imperative',
+    behaviors: [EventCaptureBehavior]
+  })
+  </script>
+</dom-module>

test/unit/gestures.html

@@ -456,6 +456,41 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         });
       });
     });
+
+    suite('Imperative API', function() {
+      var el, fn;
+      suiteSetup(function() {
+        el = document.createElement('x-imperative');
+        document.body.appendChild(el);
+        fn = function(e) { el.handle(e) };
+      });
+      suiteTeardown(function() {
+        document.body.removeChild(el);
+      });
+
+      test('add listeners with addListener', function() {
+        Polymer.Gestures.addListener(el, 'down', fn);
+        Polymer.Gestures.add(el, 'up', fn);
+        var ev = new CustomEvent('mousedown', {bubbles: true, composed: true});
+        el.dispatchEvent(ev);
+        assert.equal(el.stream.length, 1);
+        assert.equal(el.stream[0].type, 'down');
+        ev = new CustomEvent('mouseup', {bubbles: true, composed: true});
+        el.dispatchEvent(ev);
+        assert.equal(el.stream.length, 2);
+        assert.equal(el.stream[1].type, 'up');
+      })
+
+      test('remove listeners with removeListener', function() {
+        Polymer.Gestures.remove(el, 'down', fn);
+        Polymer.Gestures.removeListener(el, 'up', fn);
+        var ev = new CustomEvent('mousedown', {bubbles: true, composed: true});
+        el.dispatchEvent(ev);
+        ev = new CustomEvent('mouseup', {bubbles: true, composed: true});
+        el.dispatchEvent(ev);
+        assert.equal(el.stream.length, 2);
+      })
+    });
   </script>
 
 </body>