refactor(facade): remove DateWrapper (#12027)

modules/@angular/facade/src/lang.ts

@@ -301,19 +301,6 @@ export class Json {
   }
 }
 
-export class DateWrapper {
-  static create(
-      year: number, month: number = 1, day: number = 1, hour: number = 0, minutes: number = 0,
-      seconds: number = 0, milliseconds: number = 0): Date {
-    return new Date(year, month - 1, day, hour, minutes, seconds, milliseconds);
-  }
-  static fromISOString(str: string): Date { return new Date(str); }
-  static fromMillis(ms: number): Date { return new Date(ms); }
-  static toMillis(date: Date): number { return date.getTime(); }
-  static now(): Date { return new Date(); }
-  static toJson(date: Date): string { return date.toJSON(); }
-}
-
 export function setValueOnPath(global: any, path: string, value: any) {
   var parts = path.split('.');
   var obj: any = global;