fix: safety check for window in common module. (#8816)

* Currently if someone renders his Angular application using server side rendering, the `MatCommonModule` will throw an error due to missing `window` variable checks.

Fixes #8809

src/lib/core/common-behaviors/common-module.ts

@@ -37,6 +37,9 @@ export class MatCommonModule {
   /** Reference to the global `document` object. */
   private _document = typeof document === 'object' && document ? document : null;
 
+  /** Reference to the global 'window' object. */
+  private _window = typeof window === 'object' && window ? window : null;
+
   constructor(@Optional() @Inject(MATERIAL_SANITY_CHECKS) private _sanityChecksEnabled: boolean) {
     if (this._areChecksEnabled() && !this._hasDoneGlobalChecks) {
       this._checkDoctypeIsDefined();
@@ -52,7 +55,7 @@ export class MatCommonModule {
 
   /** Whether the code is running in tests. */
   private _isTestEnv() {
-    return window['__karma__'] || window['jasmine'];
+    return this._window && (this._window['__karma__'] || this._window['jasmine']);
   }
 
   private _checkDoctypeIsDefined(): void {
@@ -90,7 +93,11 @@ export class MatCommonModule {
 
   /** Checks whether HammerJS is available. */
   _checkHammerIsAvailable(): void {
-    if (this._areChecksEnabled() && !this._hasCheckedHammer && !window['Hammer']) {
+    if (this._hasCheckedHammer || !this._window) {
+      return;
+    }
+
+    if (this._areChecksEnabled() && !this._window['Hammer']) {
       console.warn(
         'Could not find HammerJS. Certain Angular Material components may not work correctly.');
     }

src/universal-app/prerender.ts

@@ -1,4 +1,3 @@
-import {enableProdMode} from '@angular/core';
 import {renderModuleFactory} from '@angular/platform-server';
 import {readFileSync, writeFileSync} from 'fs-extra';
 import {log} from 'gulp-util';
@@ -7,7 +6,8 @@ import 'reflect-metadata';
 import 'zone.js';
 import {KitchenSinkServerModuleNgFactory} from './kitchen-sink/kitchen-sink.ngfactory';
 
-enableProdMode();
+// Do not enable production mode, because otherwise the `MatCommonModule` won't execute
+// the browser related checks that could cause NodeJS issues.
 
 const result = renderModuleFactory(KitchenSinkServerModuleNgFactory, {
   document: readFileSync(join(__dirname, 'index.html'), 'utf-8')