RenderLayer::hasVisibleContent should ASSERT(!m_visibleContentStatusDirty)

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 8d552823065939ac2d79dc9b93914ce968276041..436824f0e07607c5b24a6236b81572465eba30eb 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -614,6 +614,15 @@ void RenderLayer::dirtyVisibleContentStatus()
         parent()->dirtyAncestorChainVisibleDescendantStatus();
 }
 
+void RenderLayer::potentiallyDirtyVisibleContentStatus(EVisibility visibility)
+{
+    if (m_visibleContentStatusDirty)
+        return;
+    if (hasVisibleContent() == (visibility == VISIBLE))
+        return;
+    dirtyVisibleContentStatus();
+}
+
 void RenderLayer::dirtyAncestorChainVisibleDescendantStatus()
 {
     for (RenderLayer* layer = this; layer; layer = layer->parent()) {