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

Source/core/rendering/RenderDeprecatedFlexibleBox.cpp

Index: Source/core/rendering/RenderDeprecatedFlexibleBox.cpp
diff --git a/Source/core/rendering/RenderDeprecatedFlexibleBox.cpp b/Source/core/rendering/RenderDeprecatedFlexibleBox.cpp
index 52f09bc3f99e46248df7abf5336706ea1b4ba71e..5d40d91d175623677b0c215040462525677686eb 100644
--- a/Source/core/rendering/RenderDeprecatedFlexibleBox.cpp
+++ b/Source/core/rendering/RenderDeprecatedFlexibleBox.cpp
@@ -670,6 +670,8 @@ void RenderDeprecatedFlexibleBox::layoutVerticalBox(bool relayoutChildren)
                 continue;
             }
 
+            child->setMayNeedInvalidation(true);
+
             SubtreeLayoutScope layoutScope(*child);
             if (!haveLineClamp && (relayoutChildren || (child->isReplaced() && (child->style()->width().isPercent() || child->style()->height().isPercent()))))
                 layoutScope.setChildNeedsLayout(child);
@@ -999,6 +1001,8 @@ void RenderDeprecatedFlexibleBox::placeChild(RenderBox* child, const LayoutPoint
 {
     LayoutRect oldRect = child->frameRect();
 
+    child->setMayNeedInvalidation(true);
+
     // Place the child.
     child->setLocation(location);