Add flag for tracking descendant paint property updates

third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp

Index: third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp
diff --git a/third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp b/third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp
index bc59d57869f2f1cd2c9e5df2f5555e721242fad7..f7764be657a11a07f087c0ff90a6194ff99e8be5 100644
--- a/third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp
+++ b/third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp
@@ -118,6 +118,8 @@ void PrePaintTreeWalk::walk(const LayoutObject& object,
               .layoutObjectInFlowThread(),
          localContext);
     object.getMutableForPainting().clearPaintInvalidationFlags();
+    object.getMutableForPainting().clearNeedsPaintPropertyUpdate();
+    object.getMutableForPainting().clearDescendantNeedsPaintPropertyUpdate();
     return;
   }
 
@@ -152,6 +154,7 @@ void PrePaintTreeWalk::walk(const LayoutObject& object,
 
   object.getMutableForPainting().clearPaintInvalidationFlags();
   object.getMutableForPainting().clearNeedsPaintPropertyUpdate();
+  object.getMutableForPainting().clearDescendantNeedsPaintPropertyUpdate();
 }
 
 }  // namespace blink