Avoid using floating point when not needed.

Source/core/layout/MultiColumnFragmentainerGroup.cpp

 // Copyright 2015 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.
 
 #include "config.h"
 
 #include "core/layout/MultiColumnFragmentainerGroup.h"
 
 #include "core/layout/LayoutMultiColumnSet.h"
 
@@ skipping 518 matching lines @@
     if (offsetInFlowThread < m_logicalTopInFlowThread)
         return 0;
     // If we're laying out right now, we cannot constrain against some logical bottom, since it
     // isn't known yet. Otherwise, just return the last column if we're past the logical bottom.
     if (mode == ClampToExistingColumns) {
         if (offsetInFlowThread >= m_logicalBottomInFlowThread)
             return actualColumnCount() - 1;
     }
 
     if (m_columnHeight)
-        return (offsetInFlowThread - m_logicalTopInFlowThread).toFloat() / m_columnHeight.toFloat();
+        return ((offsetInFlowThread - m_logicalTopInFlowThread) / m_columnHeight).floor();
     return 0;
 }
 
 unsigned MultiColumnFragmentainerGroup::columnIndexAtVisualPoint(const LayoutPoint& visualPoint) const
 {
     bool isColumnProgressionInline = m_columnSet.multiColumnFlowThread()->progressionIsInline();
     bool isHorizontalWritingMode = m_columnSet.isHorizontalWritingMode();
     LayoutUnit columnLengthInColumnProgressionDirection = isColumnProgressionInline ? m_columnSet.pageLogicalWidth() : m_columnSet.pageLogicalHeight();
     LayoutUnit offsetInColumnProgressionDirection = isHorizontalWritingMode == isColumnProgressionInline ? visualPoint.x() : visualPoint.y();
     if (!m_columnSet.style()->isLeftToRightDirection() && isColumnProgressionInline)
@@ skipping 28 matching lines @@
     append(MultiColumnFragmentainerGroup(m_columnSet));
     return last();
 }
 
 void MultiColumnFragmentainerGroupList::deleteExtraGroups()
 {
     shrink(1);
 }
 
 } // namespace blink