fix(icon): server-side error when registering icons

Fixes an error that is thrown by the `IconRegistry` when registering icons on the server side.

Fixes #6787.

src/lib/icon/icon-registry.ts

@@ -11,13 +11,21 @@ import {tap} from 'rxjs/operators/tap';
 import {finalize} from 'rxjs/operators/finalize';
 import {map} from 'rxjs/operators/map';
 import {share} from 'rxjs/operators/share';
-import {Injectable, Optional, SecurityContext, SkipSelf} from '@angular/core';
+import {
+  Injectable,
+  Inject,
+  InjectionToken,
+  Optional,
+  SecurityContext,
+  SkipSelf,
+} from '@angular/core';
 import {HttpClient} from '@angular/common/http';
 import {DomSanitizer, SafeResourceUrl} from '@angular/platform-browser';
 import {Observable} from 'rxjs/Observable';
 import {forkJoin} from 'rxjs/observable/forkJoin';
 import {of as observableOf} from 'rxjs/observable/of';
 import {_throw as observableThrow} from 'rxjs/observable/throw';
+import {DOCUMENT} from '@angular/common';
 
 
 /**
@@ -97,7 +105,10 @@ export class MatIconRegistry {
    */
   private _defaultFontSetClass = 'material-icons';
 
-  constructor(@Optional() private _httpClient: HttpClient, private _sanitizer: DomSanitizer) {}
+  constructor(
+    @Optional() private _httpClient: HttpClient,
+    @Inject(DOCUMENT) private _document: any,
+    private _sanitizer: DomSanitizer) {}
 
   /**
    * Registers an icon by URL in the default namespace.
@@ -405,7 +416,7 @@ export class MatIconRegistry {
    * Creates a DOM element from the given SVG string.
    */
   private _svgElementFromString(str: string): SVGElement {
-    const div = document.createElement('DIV');
+    const div = this._document.createElement('DIV');
     div.innerHTML = str;
     const svg = div.querySelector('svg') as SVGElement;
     if (!svg) {
@@ -482,8 +493,11 @@ export class MatIconRegistry {
 
 /** @docs-private */
 export function ICON_REGISTRY_PROVIDER_FACTORY(
-    parentRegistry: MatIconRegistry, httpClient: HttpClient, sanitizer: DomSanitizer) {
-  return parentRegistry || new MatIconRegistry(httpClient, sanitizer);
+  parentRegistry: MatIconRegistry,
+  httpClient: HttpClient,
+  document: any,
+  sanitizer: DomSanitizer) {
+  return parentRegistry || new MatIconRegistry(httpClient, document, sanitizer);
 }
 
 /** @docs-private */
@@ -493,6 +507,7 @@ export const ICON_REGISTRY_PROVIDER = {
   deps: [
     [new Optional(), new SkipSelf(), MatIconRegistry],
     [new Optional(), HttpClient],
+    DOCUMENT as InjectionToken<any>,
     DomSanitizer
   ],
   useFactory: ICON_REGISTRY_PROVIDER_FACTORY