Remove mutable from ComputedStyle by const_cast.

third_party/WebKit/Source/core/css/CSSToLengthConversionData.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 80 matching lines @@
     const ComputedStyle* style,
     const ComputedStyle* rootStyle,
     const LayoutViewItem& layoutViewItem,
     float zoom)
     : CSSToLengthConversionData(style,
                                 FontSizes(style, rootStyle),
                                 ViewportSize(layoutViewItem),
                                 zoom) {}
 
 double CSSToLengthConversionData::viewportWidthPercent() const {
-  m_style->setHasViewportUnits();
+  const_cast<ComputedStyle*>(m_style)->setHasViewportUnits();

[alancutter (OOO until 2018), 2017/04/05 05:22:23]

Let's add a TODO to plumb these bits through as output parameters instead of
const_casting.

[shend, 2017/04/05 06:19:11]

Done.

   return m_viewportSize.width() / 100;
 }
 double CSSToLengthConversionData::viewportHeightPercent() const {
-  m_style->setHasViewportUnits();
+  const_cast<ComputedStyle*>(m_style)->setHasViewportUnits();
   return m_viewportSize.height() / 100;
 }
 double CSSToLengthConversionData::viewportMinPercent() const {
-  m_style->setHasViewportUnits();
+  const_cast<ComputedStyle*>(m_style)->setHasViewportUnits();
   return std::min(m_viewportSize.width(), m_viewportSize.height()) / 100;
 }
 double CSSToLengthConversionData::viewportMaxPercent() const {
-  m_style->setHasViewportUnits();
+  const_cast<ComputedStyle*>(m_style)->setHasViewportUnits();
   return std::max(m_viewportSize.width(), m_viewportSize.height()) / 100;
 }
 
 float CSSToLengthConversionData::remFontSize() const {
-  m_style->setHasRemUnits();
+  const_cast<ComputedStyle*>(m_style)->setHasRemUnits();
   return m_fontSizes.rem();
 }
 
 double CSSToLengthConversionData::zoomedComputedPixels(
     double value,
     CSSPrimitiveValue::UnitType type) const {
   // The logic in this function is duplicated in MediaValues::computeLength()
   // because MediaValues::computeLength() needs nearly identical logic, but we
   // haven't found a way to make zoomedComputedPixels() more generic (to solve
   // both cases) without hurting performance.
@@ skipping 46 matching lines @@
     case CSSPrimitiveValue::UnitType::Chs:
       return value * chFontSize();
 
     default:
       ASSERT_NOT_REACHED();
       return 0;
   }
 }
 
 }  // namespace blink