chore(snack-bar): switch to OnPush change detection (#5515)

* Switches the snack bar component to `OnPush` change detection.
* Removes the `detectChanges` workaround for the choppy animations, because it no longer works with `OnPush`. Properly fixes the initial issue by providing a `void` animation state.

Relates to #5035.

src/lib/snack-bar/simple-snack-bar.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Component, ViewEncapsulation} from '@angular/core';
+import {Component, ViewEncapsulation, ChangeDetectionStrategy} from '@angular/core';
 import {MdSnackBarRef} from './snack-bar-ref';
 
 
@@ -20,6 +20,7 @@ import {MdSnackBarRef} from './snack-bar-ref';
   templateUrl: 'simple-snack-bar.html',
   styleUrls: ['simple-snack-bar.css'],
   encapsulation: ViewEncapsulation.None,
+  changeDetection: ChangeDetectionStrategy.OnPush,
   host: {
     'class': 'mat-simple-snackbar',
   }

src/lib/snack-bar/snack-bar-container.ts

@@ -14,6 +14,7 @@ import {
   OnDestroy,
   Renderer2,
   ElementRef,
+  ChangeDetectionStrategy,
 } from '@angular/core';
 import {
   trigger,
@@ -52,6 +53,7 @@ export const HIDE_ANIMATION = '195ms cubic-bezier(0.0,0.0,0.2,1)';
   selector: 'snack-bar-container',
   templateUrl: 'snack-bar-container.html',
   styleUrls: ['snack-bar-container.css'],
+  changeDetection: ChangeDetectionStrategy.OnPush,
   host: {
     'role': 'alert',
     '[@state]': 'animationState',
@@ -59,6 +61,7 @@ export const HIDE_ANIMATION = '195ms cubic-bezier(0.0,0.0,0.2,1)';
   },
   animations: [
     trigger('state', [
+      state('void', style({transform: 'translateY(100%)'})),
       state('initial', style({transform: 'translateY(100%)'})),
       state('visible', style({transform: 'translateY(0%)'})),
       state('complete', style({transform: 'translateY(100%)'})),

src/lib/snack-bar/snack-bar.ts

@@ -135,12 +135,6 @@ export class MdSnackBar {
     let containerPortal = new ComponentPortal(MdSnackBarContainer, config.viewContainerRef);
     let containerRef: ComponentRef<MdSnackBarContainer> = overlayRef.attach(containerPortal);
     containerRef.instance.snackBarConfig = config;
-
-    // The snackbar animation needs the content to be resolved in order to transform the bar
-    // out of the view initially (so it can slide in). To make the content resolve, we manually
-    // detect changes.
-    containerRef.changeDetectorRef.detectChanges();
-
     return containerRef.instance;
   }