void CompositorPendingAnimations::notifyCompositorAnimationStarted(double monotonicAnimationStartTime)
{
    for (size_t i = 0; i < m_waitingForCompositorAnimationStart.size(); ++i) {
        AnimationPlayer* player = m_waitingForCompositorAnimationStart[i].get();
        player->setStartTimeInternal(monotonicAnimationStartTime - player->timeline()->zeroTime(), true);
    }

    m_waitingForCompositorAnimationStart.clear();
}
AnimationPlayer* AnimationTimeline::play(AnimationNode* child)
{
    if (!m_document)
        return 0;
    AnimationPlayer* player = createAnimationPlayer(child);
    player->setStartTimeInternal(effectiveTime());
    m_document->compositorPendingAnimations().add(player);
    return player;
}