getClientRects() shouldn't clip against any ancestors.

third_party/WebKit/Source/core/layout/FragmentainerIterator.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef FragmentainerIterator_h
 #define FragmentainerIterator_h
 
+#include "core/layout/MultiColumnFragmentainerGroup.h"
 #include "platform/geometry/LayoutRect.h"
 
 namespace blink {
 
 class LayoutFlowThread;
 class LayoutMultiColumnSet;
-class MultiColumnFragmentainerGroup;
 
 // Used to find the fragmentainers that intersect with a given portion of the
 // flow thread. The portion typically corresponds to the bounds of some
 // descendant layout object. The iterator walks in block direction order.
 class FragmentainerIterator {
  public:
   // Initialize the iterator, and move to the first fragmentainer of interest.
   // The clip rectangle is optional. If it's empty, it means that no clipping
   // will be performed, and that the only thing that can limit the set of
   // fragmentainers to visit is |physicalBoundingBox|.
   FragmentainerIterator(
       const LayoutFlowThread&,
       const LayoutRect& physicalBoundingBoxInFlowThread,
       const LayoutRect& clipRectInMulticolContainer = LayoutRect());
 
   // Advance to the next fragmentainer. Not allowed to call this if atEnd() is
   // true.
   void advance();
 
   // Return true if we have walked through all relevant fragmentainers.
   bool atEnd() const { return !m_currentColumnSet; }
 
   // The physical translation to apply to shift the box when converting from
   // flowthread to visual coordinates.
   LayoutSize paginationOffset() const;
 
-  // Return the physical content box of the current fragmentainer, relative to
-  // the flow thread.
-  LayoutRect fragmentainerInFlowThread() const;
-
   // Return the physical clip rectangle of the current fragmentainer, relative
   // to the flow thread.
-  LayoutRect clipRectInFlowThread() const;
+  LayoutRect clipRectInFlowThread(
+      MultiColumnFragmentainerGroup::ClipRectAxesSelector =
+          MultiColumnFragmentainerGroup::BothAxes) const;
 
  private:
   const LayoutFlowThread& m_flowThread;
   const LayoutRect m_clipRectInMulticolContainer;
 
   const LayoutMultiColumnSet* m_currentColumnSet;
   unsigned m_currentFragmentainerGroupIndex;
   unsigned m_currentFragmentainerIndex;
   unsigned m_endFragmentainerIndex;
 
   LayoutUnit m_logicalTopInFlowThread;
   LayoutUnit m_logicalBottomInFlowThread;
 
   const MultiColumnFragmentainerGroup& currentGroup() const;
   void moveToNextFragmentainerGroup();
   bool setFragmentainersOfInterest();
   void setAtEnd() { m_currentColumnSet = nullptr; }
   bool hasClipRect() const { return !m_clipRectInMulticolContainer.isEmpty(); }
 };
 
 }  // namespace blink
 
 #endif  // FragmentainerIterator_h