fix(focus-monitor): server-side rendering error when using focusVia (#10729)

Fixes an error that is being thrown by `focusVia` when it's used on the server.

Author: crisbeto

src/cdk/a11y/focus-monitor/focus-monitor.ts

@@ -140,7 +140,11 @@ export class FocusMonitor implements OnDestroy {
    */
   focusVia(element: HTMLElement, origin: FocusOrigin): void {
     this._setOriginForCurrentEventQueue(origin);
-    element.focus();
+
+    // `focus` isn't available on the server
+    if (typeof element.focus === 'function') {
+      element.focus();
+    }
   }
 
   ngOnDestroy() {

src/universal-app/kitchen-sink/kitchen-sink.ts

@@ -3,7 +3,7 @@ import {
   CdkTableModule,
   DataSource
 } from '@angular/cdk/table';
-import {Component, NgModule} from '@angular/core';
+import {Component, ElementRef, NgModule} from '@angular/core';
 import {
   MatAutocompleteModule,
   MatBadgeModule,
@@ -44,6 +44,7 @@ import {
 } from '@angular/material';
 import {BrowserModule} from '@angular/platform-browser';
 import {ServerModule} from '@angular/platform-server';
+import {FocusMonitor} from '@angular/cdk/a11y';
 import {Observable, of as observableOf} from 'rxjs';
 
 export class TableDataSource extends DataSource<any> {
@@ -77,7 +78,10 @@ export class KitchenSink {
   constructor(
     snackBar: MatSnackBar,
     dialog: MatDialog,
-    viewportRuler: ViewportRuler) {
+    viewportRuler: ViewportRuler,
+    focusMonitor: FocusMonitor,
+    elementRef: ElementRef<HTMLElement>) {
+    focusMonitor.focusVia(elementRef.nativeElement, 'program');
     snackBar.open('Hello there');
     dialog.open(TestDialog);