NSArray *httpCookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookiesForURL:httpUrl];
@Override
public void onPageFinished(WebView view, String url){
String cookies = CookieManager.getInstance().getCookie(url);
Log.d(TAG, "All the cookies in a string:" + cookies);
}
https://developer.android.com/reference/android/webkit/CookieSyncManager.html
webview.eval can work however to get cookie data, I think