void MediaSourceRegistry::registerURL(SecurityOrigin*, const KURL& url, URLRegistrable* registrable)
{
    DCHECK_EQ(&registrable->registry(), this);
    DCHECK(isMainThread());

    MediaSource* source = static_cast<MediaSource*>(registrable);
    source->addedToRegistry();
    m_mediaSources.set(url.getString(), source);
}
void MediaSourceRegistry::registerURL(SecurityOrigin*, const URL& url, URLRegistrable* registrable)
{
    ASSERT(&registrable->registry() == this);
    ASSERT(isMainThread());

    MediaSource* source = static_cast<MediaSource*>(registrable);
    source->addedToRegistry();
    m_mediaSources.set(url.string(), source);
}