  std::u16string InsertCSS(v8::Isolate* isolate,
                           const std::string& css,
                           gin::Arguments* args) {
    blink::WebDocument::CSSOrigin css_origin =
        blink::WebDocument::CSSOrigin::kAuthorOrigin;

    gin_helper::Dictionary options;
    if (args->GetNext(&options))
      options.Get("cssOrigin", &css_origin);

    content::RenderFrame* render_frame;
    if (!MaybeGetRenderFrame(isolate, "insertCSS", &render_frame))
      return std::u16string();

    blink::WebFrame* web_frame = render_frame->GetWebFrame();
    if (web_frame->IsWebLocalFrame()) {
      return web_frame->ToWebLocalFrame()
          ->GetDocument()
          .InsertStyleSheet(blink::WebString::FromUTF8(css), nullptr,
                            css_origin)
          .Utf16();
    }
    return std::u16string();
  }
  std::u16string InsertCSS(v8::Isolate* isolate,
                           const std::string& css,
                           gin::Arguments* args) {
    blink::WebDocument::CSSOrigin css_origin =
        blink::WebDocument::CSSOrigin::kAuthorOrigin;

    gin_helper::Dictionary options;
    if (args->GetNext(&options))
      options.Get("cssOrigin", &css_origin);

    content::RenderFrame* render_frame;
    if (!MaybeGetRenderFrame(isolate, "insertCSS", &render_frame))
      return std::u16string();

    blink::WebFrame* web_frame = render_frame->GetWebFrame();
    if (web_frame->IsWebLocalFrame()) {
      return web_frame->ToWebLocalFrame()
          ->GetDocument()
          .InsertStyleSheet(blink::WebString::FromUTF8(css), nullptr,
                            css_origin)
          .Utf16();
    }
    return std::u16string();
  }