Mark when we may have been invalidated to early out on repaintTreeAfterLayout.

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index 45651e735992acb0c0dabfcb51ffd305888decb6..a20505c27025377f16e26c1c86e02e12a1af0372 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -1512,6 +1512,11 @@ const char* RenderObject::invalidationReasonToString(InvalidationReason reason)
 
 void RenderObject::repaintTreeAfterLayout()
 {
+    // If we didn't need invalidation then our children don't need as well.
+    // Skip walking down the tree as everything should be fine below us.
+    if (!mayNeedInvalidation())
+        return;
+
     clearRepaintState();
 
     for (RenderObject* child = firstChild(); child; child = child->nextSibling()) {
@@ -3398,6 +3403,7 @@ void RenderObject::clearRepaintState()
     setShouldDoFullRepaintIfSelfPaintingLayer(false);
     setShouldRepaintOverflow(false);
     setLayoutDidGetCalled(false);
+    setMayNeedInvalidation(false);
 }
 
 } // namespace WebCore