Document: close() メソッド
Deprecated
Avoid using this feature in new projects.
The dynamic markup insertion API, which includes document.write(), has "very idiosyncratic behavior" which can be difficult to debug.
This feature may be a candidate for removal from web standards or browsers.>
Consider using the following features instead: DOM.>
Document.close() メソッドは、 Document.open() で開かれた文書への書き込みを終了します。