ResourceClient.
class ResourceClient extends XWalkResourceClient {
    public ResourceClient(XWalkView xwalkView) {
        super(xwalkView);
    }
    public void onLoadStarted(XWalkView view, String url) {
        mProgress = (ProgressBar) findViewById(R.id.progressBar);
        mProgress.setVisibility(View.VISIBLE);
        super.onLoadStarted(view, url);
        Log.d("INFO", "Load Started:" + url);
    }
    public void onLoadFinished(XWalkView view, String url) {
        super.onLoadFinished(view, url);
        Log.d("INFO", "Load Finished:" + url);
        bottomBar = (BottomBar) findViewById(R.id.bottomBar);
        mProgress = (ProgressBar) findViewById(R.id.progressBar);
        mProgress.setVisibility(View.GONE);
    }
    public void onProgressChanged(XWalkView view, int progressInPercent) {
        super.onProgressChanged(view, progressInPercent);
        Log.d("INFO", "Loading Progress:" + progressInPercent);
        mProgress = (ProgressBar) findViewById(R.id.progressBar);
        mProgress.setProgress(progressInPercent);
    }