fix(ngAnimate): remove event listeners only after all listeners have been called

The fix for removing the event callbacks on destroy introduced in
ce7f400 removed the events too early, so that the event callbacks
for the "close" phase in "leave" animations were not called.

This commit fixes the behavior so that the event callbacks are only removed during on('$destroy')
when no animation is currently active on the element. When an animation is active, the event callbacks
will be removed after all callbacks have run, and if the element has no parent (has been removed from
the DOM).

Closes #14321

Author: Narretz

src/ngAnimate/animateQueue.js

@@ -208,6 +208,14 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
       });
     }
 
+    function cleanupEventListeners(phase, element) {
+      if (phase === 'close' && !element[0].parentNode) {
+        // If the element is not attached to a parentNode, it has been removed by
+        // the domOperation, and we can safely remove the event callbacks
+        $animate.off(element);
+      }
+    }
+
     var $animate = {
       on: function(event, container, callback) {
         var node = extractElementNode(container);
@@ -219,7 +227,14 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
 
         // Remove the callback when the element is removed from the DOM
         jqLite(container).on('$destroy', function() {
-          $animate.off(event, container, callback);
+          var animationDetails = activeAnimationsLookup.get(node);
+
+          if (!animationDetails) {
+            // If there's an animation ongoing, the callback calling code will remove
+            // the event listeners. If we'd remove here, the callbacks would be removed
+            // before the animation ends
+            $animate.off(event, container, callback);
+          }
         });
       },
 
@@ -552,7 +567,10 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
               forEach(callbacks, function(callback) {
                 callback(element, phase, data);
               });
+              cleanupEventListeners(phase, element);
             });
+          } else {
+            cleanupEventListeners(phase, element);
           }
         });
         runner.progress(event, phase, data);