[MatSidenav] Sidenav Toggling Can Cause Content Shifting

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

#### What is the expected behavior?
Mat-sidenav-content is not moved from original position upon quick mat-sidenav toggles

#### What is the current behavior?
Quick mat-sidenav toggles can cause mat-sidenav-content to be shifted over until the drawer is toggled again

#### What are the steps to reproduce?

Set the autofocus on mat-sidenav to true, and place a focusable input in the mat-sidenav
Click the 'open drawer' button quickly and repeatedly until the content shifts. Click the button again and the content will shift back.

https://stackblitz.com/edit/angular-eesonu

#### What is the use-case or motivation for changing an existing behavior?
Use-case: User accidentally opens the drawer and quickly presses again to undo the action. This will result in possibly all content on the page not being displayed.

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?
Angular: 6.0.9
Material: 6.4.1

Commencez par reproduire le comportement dans le StackBlitz associé avec autofocus activé et un input pouvant recevoir le focus à l’intérieur de MatSidenav, puis examinez le comportement de MatSidenav et de mat-sidenav-content lors de basculements rapides. Le travail est terminé lorsque des actions répétées d’ouverture et de fermeture ne laissent plus mat-sidenav-content décalé et qu’un basculement ultérieur n’est pas nécessaire pour restaurer sa position.

Rédigé par le modèle d'indexation à partir du texte de l'issue.