Add test that late resolved functions don't warn

test/unit/bind-elements.html

@@ -621,3 +621,34 @@
     })();
   </script>
 </dom-module>
+
+<dom-module id="x-bind-computed-property-late-translator">
+  <template>
+    <div id="check">[[translate(message)]]</div>
+  </template>
+  <script>
+    Polymer({
+      is: 'x-bind-computed-property-late-translator',
+      properties: {
+        message: {
+          type: String,
+          value: 'Hello'
+        },
+        translate: {
+          type: Function,
+          computed: '_computeTranslateFn(translator)'
+        },
+        translator: {
+          type: Function,
+        },
+      },
+
+      _computeTranslateFn: function(translator) {
+        return function(message) {
+          return translator(message);
+        }
+      },
+
+    });
+  </script>
+</dom-module>

test/unit/bind.html

@@ -310,6 +310,19 @@ suite('computed bindings with dynamic functions', function() {
     assert.equal(el.$.check.textContent, 'changed: Hello World.');
   });
 
+  test('annotated computation / late resolved dynamic function', function() {
+    el = document.createElement('x-bind-computed-property-late-translator');
+    document.body.appendChild(el);
+
+    assert.equal(el.$.check.textContent.trim(), '');
+
+    el.translator = function(message) {
+      return 'translated: ' + message;
+    };
+
+    assert.equal(el.$.check.textContent, 'translated: Hello');
+  });
+
   test('observer with dynamic function', function() {
     Polymer({
       is: 'x-observer-with-dynamic-function',