Merge pull request #74 from edusperoni/fix/hxr-httpformdata

fix: allow HttpFormData in NSHTTPXMLHttpRequest

Author: jerbob92

src/angular/xhr.ts

@@ -1,7 +1,7 @@
 import {XhrFactory } from "@angular/common/http";
 import {Injectable} from "@angular/core";
 import * as types from "@nativescript/core/utils/types";
-import { request } from "..";
+import { request, HTTPFormData } from "..";
 import { HttpRequestOptions, HttpResponse, Trace } from "@nativescript/core";
 
 namespace XMLHttpRequestResponseType {
@@ -261,7 +261,7 @@ export class NSHTTPXMLHttpRequest {
 
             // @ts-ignore
             this._options.content = Blob.InternalAccessor.getBuffer(data);
-        } else if (data instanceof ArrayBuffer) {
+        } else if (data instanceof ArrayBuffer || data instanceof HTTPFormData) {
             this._options.content = data;
         }