message: Update window.service.ts
diff: @@ -6,7 +6,7 @@ import { Injectable } from '@angular/core';
  *
  * @return {Object} window The native window object
  */
  -function _window(): any {
  +function _window(): Window {
  // return the native window object
  return window;
  }
  @@ -22,7 +22,7 @@ export class TsWindowService {
  *
  * @return {Object} _window The function that returns the native window object
  */
  - get nativeWindow(): any {
  + get nativeWindow(): Window {
  return _window();
  }
  