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 d4066edfdcf817e8624714fbcad507197e657139..5c355e72175f2df2b85557ac3c216690e29c6ab3 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -617,6 +617,15 @@ 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()) {