Fix focus ring damage sometimes being 1 pixel off.

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 2207 matching lines @@
 
 void ComputedStyle::setOffsetPath(PassRefPtr<StylePath> path) {
   m_rareNonInheritedData.access()->m_transform.access()->m_motion.m_path = path;
 }
 
 int ComputedStyle::outlineOutsetExtent() const {
   if (!hasOutline())
     return 0;
   if (outlineStyleIsAuto()) {
     return GraphicsContext::focusRingOutsetExtent(
-        outlineOffset(), getOutlineStrokeWidthForFocusRing());
+        outlineOffset(), std::ceil(getOutlineStrokeWidthForFocusRing()));
   }
   return std::max(0, saturatedAddition(outlineWidth(), outlineOffset()));
 }
 
 float ComputedStyle::getOutlineStrokeWidthForFocusRing() const {
 #if OS(MACOSX)
   return outlineWidth();
 #else
   // Draw an outline with thickness in proportion to the zoom level, but never
   // less than 1 pixel so that it remains visible.
@@ skipping 161 matching lines @@
     if (value < 0)
       fvalue -= 0.5f;
     else
       fvalue += 0.5f;
   }
 
   return roundForImpreciseConversion<int>(fvalue / zoomFactor);
 }
 
 }  // namespace blink