@TargetApi(Build.VERSION_CODES.M)
        public void onPageCommitVisible(WebView view, String url) {
            if (webViewClient != null) {
                webViewClient.onPageCommitVisible(view, url);
            } else {
                super.onPageCommitVisible(view, url);
            }
        }
This method can be called in any thread, and if it is not called in the main thread,
it will be automatically distributed to the main thread.

@param url
@param additionalHttpHeaders
app/src/main/java/com/example/jingbin/webviewstudy/view/WVJBWebView.java