Let siblings layout if an adjacent float may no longer affect them

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 671 matching lines @@
     mark_descendants_with_floats = true;
   } else if (UNLIKELY(new_logical_top.MightBeSaturated())) {
     // The logical top might be saturated for very large elements. Comparing
     // with the old logical top might then yield a false negative, as adding and
     // removing margins, borders etc. from a saturated number might yield
     // incorrect results. If this is the case, always mark for layout.
     mark_descendants_with_floats = true;
   } else if (!child.AvoidsFloats() || child.ShrinkToAvoidFloats()) {
     // If an element might be affected by the presence of floats, then always
     // mark it for layout.
-    if (std::max(previous_float_logical_bottom, LowestFloatLogicalBottom()) >
-        new_logical_top)
+    LayoutUnit lowest_float =
+        std::max(previous_float_logical_bottom, LowestFloatLogicalBottom());
+    lowest_float = std::max(lowest_float, child.LowestFloatLogicalBottom());
+    if (lowest_float > new_logical_top)
       mark_descendants_with_floats = true;
   }
 
   if (mark_descendants_with_floats)
     child.MarkAllDescendantsWithFloatsForLayout();
 }
 
 bool LayoutBlockFlow::PositionAndLayoutOnceIfNeeded(
     LayoutBox& child,
     LayoutUnit new_logical_top,
@@ skipping 3951 matching lines @@
   return LayoutBlock::InvalidatePaintIfNeeded(paint_invalidation_state);
 }
 
 void LayoutBlockFlow::InvalidateDisplayItemClients(
     PaintInvalidationReason invalidation_reason) const {
   BlockFlowPaintInvalidator(*this).InvalidateDisplayItemClients(
       invalidation_reason);
 }
 
 }  // namespace blink