void MediaDecoder::NotifyOwnerActivityChanged(bool aIsVisible) { MOZ_ASSERT(NS_IsMainThread()); MOZ_DIAGNOSTIC_ASSERT(!IsShutdown()); SetElementVisibility(aIsVisible); MediaDecoderOwner* owner = GetOwner(); NS_ENSURE_TRUE_VOID(owner); dom::HTMLMediaElement* element = owner->GetMediaElement(); NS_ENSURE_TRUE_VOID(element); RefPtr<LayerManager> layerManager = nsContentUtils::LayerManagerForDocument(element->OwnerDoc()); NS_ENSURE_TRUE_VOID(layerManager); RefPtr<KnowsCompositor> knowsCompositor = layerManager->AsShadowForwarder(); mCompositorUpdatedEvent.Notify(knowsCompositor); }