Bug, feature request, or proposal:
Bug
What is the expected behavior?
Scrolling should appear after the size of the dialog will exceed 80vw
What is the current behavior?
When you use the md-hint/md-error, scrolling is always shown

What are the steps to reproduce?
Providing a Plunker (or similar) is the best way to get the team to see your issue.
Plunker template: https://plnkr.co/edit/yLf4Cc0k4GwH5BrXNXnX?p=preview
What is the use-case or motivation for changing an existing behavior?
Which versions of Angular, Material, OS, browsers are affected?
material 2.0.0-beta.3 Angular 4.0.2
Is there anything else we should know?