Repaint selection when element with ::selection style is recalculated.

third_party/WebKit/Source/core/style/ComputedStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2011 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 554 matching lines @@
     if (dependenceOnContentHeightHasChanged(*this, other))
       diff.setNeedsFullLayout();
     else
       diff.setNeedsPositionedMovementLayout();
   }
 
   if (diffNeedsPaintInvalidationSubtree(other))
     diff.setNeedsPaintInvalidationSubtree();
   else if (diffNeedsPaintInvalidationObject(other))
     diff.setNeedsPaintInvalidationObject();
+  else if (diffNeedsPaintInvalidationSelection(other))
+    diff.setNeedsPaintInvalidationSelection();
 
   updatePropertySpecificDifferences(other, diff);
 
   // The following condition needs to be at last, because it may depend on
   // conditions in diff computed above.
   if (scrollAnchorDisablingPropertyChanged(other, diff))
     diff.setScrollAnchorDisablingPropertyChanged();
 
   // Cursors are not checked, since they will be set appropriately in response
   // to mouse events, so they don't need to cause any paint invalidation or
@@ skipping 428 matching lines @@
     for (const AtomicString& property :
          *value->customInvalidationProperties()) {
       if (!dataEquivalent(getVariable(property), other.getVariable(property)))
         return true;
     }
   }
 
   return false;
 }
 
+bool ComputedStyle::diffNeedsPaintInvalidationSelection(
+    const ComputedStyle& other) const {
+  return hasPseudoStyle(PseudoIdSelection) ||
+         other.hasPseudoStyle(PseudoIdSelection);
+}
+
 void ComputedStyle::updatePropertySpecificDifferences(
     const ComputedStyle& other,
     StyleDifference& diff) const {
   if (m_box->zIndex() != other.m_box->zIndex() ||
       isStackingContext() != other.isStackingContext())
     diff.setZIndexChanged();
 
   if (m_rareNonInheritedData.get() != other.m_rareNonInheritedData.get()) {
     if (!transformDataEquivalent(other) ||
         m_rareNonInheritedData->m_perspective !=
@@ skipping 1437 matching lines @@
     if (value < 0)
       fvalue -= 0.5f;
     else
       fvalue += 0.5f;
   }
 
   return roundForImpreciseConversion<int>(fvalue / zoomFactor);
 }
 
 }  // namespace blink