xhr.withCredential with TextureHandler

[jinwoobot]

Description

I tried to set crossOrigin = "anonymous" using assetPrefix: true
it's works well except texture(401 error)

• this.app = new pc.Application(this.canvas, {
  mouse: new pc.Mouse(this.canvas),
  assetPrefix: true,
  });

so I add below code

• this.app.loader._handlers.texture.crossOrigin = 'use-credentials';

and tried to find http options in TextHandler.load
but, It's {retry:this.retryRequests} set by default.

I think user can change this options.

Not engine code change like below

• xhr = new XMLHttpRequest;
  xhr.open(method, url, options.async);
  options.withCredentials = true; //Add quick fix solution
  xhr.withCredentials = options.withCredentials !== undefined ? options.withCredentials : false;