env.d.ts

interface ShadyCSS {
  nativeCss: boolean;
  nativeShadow: boolean;
  styleElement(host: Element, overrideProps?: {[key: string]: string}): void;
  prepareTemplateDom(template: Element, elementName: string): void;
  prepareTemplateStyles(
      template: Element, elementName: string, typeExtension?: string): void;
  ScopingShim: undefined|{
    prepareAdoptedCssText(
        cssTextArray: Array<string>, elementName: string): void;
  };
}

interface ShadyDOM {
  inUse: boolean;
}

interface Window {
  ShadyCSS?: ShadyCSS;
  ShadyDOM?: ShadyDOM;
}