Apply 'x-content-type-options' check to dynamically inserted script.

BUG=348581

Review URL: https://codereview.chromium.org/185593011

git-svn-id: svn://svn.chromium.org/blink/trunk@168570 bbb929c8-8fbe-4397-9dbb-9b2b20218538
ScriptLoaderClient* ScriptLoader::client() const
{
    if (isHTMLScriptLoader(m_element))
        return toHTMLScriptElement(m_element);

    if (isSVGScriptLoader(m_element))
        return toSVGScriptElement(m_element);

    ASSERT_NOT_REACHED();
    return 0;
}

ScriptLoaderClient* ScriptLoader::client() const
{
    if (isHTMLScriptLoader(m_element))
        return toHTMLScriptElement(m_element);

    if (isSVGScriptLoader(m_element))
        return toSVGScriptElement(m_element);

    ASSERT_NOT_REACHED();
    return 0;
}
