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

Source/core/rendering/RenderFlexibleBox.cpp

Index: Source/core/rendering/RenderFlexibleBox.cpp
diff --git a/Source/core/rendering/RenderFlexibleBox.cpp b/Source/core/rendering/RenderFlexibleBox.cpp
index aa4c8f483e25e359591432c1578e6f578319aa06..2395e4a874a331f929f40bc64fa489fd9b48fc2c 100644
--- a/Source/core/rendering/RenderFlexibleBox.cpp
+++ b/Source/core/rendering/RenderFlexibleBox.cpp
@@ -1110,6 +1110,9 @@ void RenderFlexibleBox::layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, cons
             continue;
         }
 
+        // FIXME Investigate if this can be removed based on other flags. crbug.com/370010
+        child->setMayNeedInvalidation(true);
+
         LayoutUnit childPreferredSize = childSizes[i] + mainAxisBorderAndPaddingExtentForChild(child);
         setLogicalOverrideSize(child, childPreferredSize);
         if (childPreferredSize != mainAxisExtentForChild(child)) {