fix(input): fix invalid animation for input.

At the moment the animation will stuck if there is no `md-auto-hide` class or the class isn't `md-input-invalid`.
That's because we not trigger the callback if we finish the animation.

Fixes #6822. Closes #6880

src/components/input/demoErrors/index.html

@@ -56,9 +56,10 @@
             {{projectForm.rate.$viewValue | currency:"$":0}} an hour? That's a little ridiculous. I
             doubt event Bill Clinton could afford that.
           </div>
-
-          Make sure to include <a href="https://docs.angularjs.org/api/ngMessages" target="_blank">angular-messages</a> module when using ng-message.
         </div>
+        <p>
+          Make sure to include <a href="https://docs.angularjs.org/api/ngMessages" target="_blank">ngMessages</a> module when using ng-message markup.
+        </p>
       </md-input-container>
     </form>
   </md-content>

src/components/input/demoErrors/style.css

@@ -1 +1,8 @@
 .inputErrorsApp { min-height:48px; }
+
+
+md-input-container > p {
+    font-size: 0.8em;
+    text-align: left;
+    width:100%;
+}

src/components/input/input.js

@@ -615,6 +615,8 @@ function mdInputInvalidMessagesAnimation($q, $animateCss) {
 
       if (className == "md-input-invalid" && messages.hasClass('md-auto-hide')) {
         showInputMessages(element, $animateCss, $q).finally(done);
+      } else {
+        done();
       }
     }