message: Fixed charts by loading the library inside the constructor.
diff: import { types } from "../client-api";
  import * as ui from "../ui";
  -// tslint:disable-next-line:no-string-literal
  -const Microsoft = typeof window !== "undefined" ? window["Microsoft"] : undefined;
  -export const DefaultHost = (Microsoft && Microsoft.Charts) ?
  - new Microsoft.Charts.Host({ base: "https://charts.microsoft.com" }) : null;
  -
  export class Chart extends ui.Component {
  private chart: any;
  private lastSize: ui.ISize = { width: -1, height: -1 };
  - constructor(element: HTMLDivElement, private cell: types.ICell, host = DefaultHost) {
  + constructor(element: HTMLDivElement, private cell: types.ICell) {
  super(element);
  - this.chart = new Microsoft.Charts.Chart(host, element);
  + // tslint:disable-next-line:no-string-literal
  + const Microsoft = typeof window !== "undefined" ? window["Microsoft"] : undefined;
  + const DefaultHost = (Microsoft && Microsoft.Charts) ?
  + new Microsoft.Charts.Host({ base: "https://charts.microsoft.com" }) : null;
  + this.chart = new Microsoft.Charts.Chart(DefaultHost, element);
  this.chart.setRenderer(Microsoft.Charts.IvyRenderer.Svg);
  this.cell.on("valueChanged", () => {
  