Hey!

What is the current behavior?
When you have a form that is shown using ngIf and contain an <input type="email" ng-model="someModel" required>, ngAnimate classes are not added when the ngIf statement becomes truthy.

Steps to reproduce
Link to demo

1. Create a form that is shown with ngIf and contains an <input type="email" ng-model="someModel" required>
2. Make ngIf statement truthy

What is the expected behavior?
ngAnimate classes should be added when ngIf statement becomes truthy.

What is the motivation / use case for changing the behavior?
Consistent behavior

Affected:
This occured when I tested with Chrome and Firefox on Linux, Safari on OSX, and Chrome / IE on Win7, both angular 1.5.x stable and snapshot.

Other information
It works as expected if:

1. type="email" is changed to something else
2. required is removed
3. ngShow / ngHide is used instead of ngIf