#### Bug, feature request, or proposal:
feature request

#### What is the expected behavior?
I'd like to use something like this (just like `mat-menu`):
```
Open it

Dialog Title

Content


Cancel
Confirm

```

#### What is the current behavior?
Doesn't exist as fat as I have seen in the docs and source code.

#### What are the steps to reproduce?
I've created a small component which demonstrates what I'm looking for:
https://stackblitz.com/edit/angular-material2-issue-tp5aej?file=app%2Fapp.component.html
(I didn't get `mat-dialog-close` working with the projection, though I chose to just add a method to my dialog component)

#### What is the use-case or motivation for changing an existing behavior?
There are many use cases where I just want a very simple dialog, and don't want to write 30 lines of code.

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?
Angular 6 beta
Material 6 beta

リンク先の StackBlitz 例、特に app/app.component.html から始め、要求されている mat-dialog のインライン使用方法を、既存の Material dialog のドキュメントおよびソースと比較します。投影コンテンツと mat-dialog-close をサポートできるかを判断し、そのうえでダイアログを開いて選択された結果を返すために必要な API とテストを定義します。

索引モデルが issue の本文から書いたものです。