fix(platform): don't shadow window (#4622)

Author: jelbourn

src/lib/core/platform/platform.ts

@@ -1,12 +1,8 @@
 import {Injectable} from '@angular/core';
 
-declare const window: any;
-
 // Whether the current platform supports the V8 Break Iterator. The V8 check
 // is necessary to detect all Blink based browsers.
-const hasV8BreakIterator = typeof(window) !== 'undefined' ?
-    (window.Intl && (window.Intl as any).v8BreakIterator) :
-    (typeof(Intl) !== 'undefined' && (Intl as any).v8BreakIterator);
+const hasV8BreakIterator = (typeof(Intl) !== 'undefined' && (Intl as any).v8BreakIterator);
 
 /**
  * Service to detect the current platform by comparing the userAgent strings and
@@ -22,14 +18,14 @@ export class Platform {
   TRIDENT = /(msie|trident)/i.test(navigator.userAgent);
 
   // EdgeHTML and Trident mock Blink specific things and need to be excluded from this check.
-  BLINK = !!(window.chrome || hasV8BreakIterator) && !!CSS && !this.EDGE && !this.TRIDENT;
+  BLINK = !!((window as any).chrome || hasV8BreakIterator) && !!CSS && !this.EDGE && !this.TRIDENT;
 
   // Webkit is part of the userAgent in EdgeHTML, Blink and Trident. Therefore we need to
   // ensure that Webkit runs standalone and is not used as another engine's base.
   WEBKIT = /AppleWebKit/i.test(navigator.userAgent) && !this.BLINK && !this.EDGE && !this.TRIDENT;
 
   /** Browsers and Platform Types */
-  IOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;
+  IOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !(window as any).MSStream;
 
   // It's difficult to detect the plain Gecko engine, because most of the browsers identify
   // them self as Gecko-like browsers and modify the userAgent's according to that.