There's no class A break point before or after a float.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 2008 matching lines @@
 
 EBreak LayoutBox::joinFragmentainerBreakValues(EBreak firstValue, EBreak secondValue)
 {
     if (fragmentainerBreakPrecedence(secondValue) >= fragmentainerBreakPrecedence(firstValue))
         return secondValue;
     return firstValue;
 }
 
 EBreak LayoutBox::classABreakPointValue(EBreak previousBreakAfterValue) const
 {
+    // First assert that we're at a class A break point.
     ASSERT(isBreakBetweenControllable(previousBreakAfterValue));
+
     return joinFragmentainerBreakValues(previousBreakAfterValue, breakBefore());
 }
 
 bool LayoutBox::needsForcedBreakBefore(EBreak previousBreakAfterValue) const
 {
-    return isForcedFragmentainerBreakValue(classABreakPointValue(previousBreakAfterValue));
+    // Forced break values are only honored when specified on in-flow objects, but floats and
+    // out-of-flow positioned objects may be affected by a break-after value of the previous
+    // in-flow object, even though we're not at a class A break point.
+    EBreak breakValue = isFloatingOrOutOfFlowPositioned()
+        ? previousBreakAfterValue : classABreakPointValue(previousBreakAfterValue);
+    return isForcedFragmentainerBreakValue(breakValue);
 }
 
 bool LayoutBox::paintedOutputOfObjectHasNoEffect() const
 {
     // In case scrollbars got repositioned (which will typically happen if the box got
     // resized), we cannot skip invalidation.
     if (hasNonCompositedScrollbars())
         return false;
 
     // Cannot skip paint invalidation if the box has real things to paint.
@@ skipping 2942 matching lines @@
         m_rareData->m_snapAreas->remove(&snapArea);
     }
 }
 
 SnapAreaSet* LayoutBox::snapAreas() const
 {
     return m_rareData ? m_rareData->m_snapAreas.get() : nullptr;
 }
 
 } // namespace blink