Remove WebFrame::canHaveSecureChild

To simplify the public API, ServiceWorkerNetworkProvider can do the
parent walk itself.

Follow-up to https://crrev.com/ad1850962644e19.

BUG=607543

Review-Url: https://codereview.chromium.org/2082493002
Cr-Commit-Position: refs/heads/master@{#400896}
void Document::close()
{
    if (!scriptableDocumentParser() || !scriptableDocumentParser()->wasCreatedByScript() || !scriptableDocumentParser()->isParsing())
        return;

    if (DocumentParser* parser = m_parser)
        parser->finish();

    if (!m_frame) {
        implicitClose();
        return;
    }

    m_frame->loader().checkCompleted();
}

void Document::close()
{
    if (!scriptableDocumentParser() || !scriptableDocumentParser()->wasCreatedByScript() || !scriptableDocumentParser()->isParsing())
        return;

    if (DocumentParser* parser = m_parser)
        parser->finish();

    if (!m_frame) {
        implicitClose();
        return;
    }

    m_frame->loader().checkCompleted();
}
