[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

Start by reproducing the behavior in the linked StackBlitz with autofocus enabled and a focusable input inside MatSidenav, then inspect the MatSidenav and mat-sidenav-content behavior during rapid toggles. Done means repeated open-and-close actions no longer leave mat-sidenav-content shifted, and a subsequent toggle is not needed to restore its position.

Written by the indexing model from the issue text.