Add helper for computing outset for 'outline'

Source/core/paint/InlinePainter.cpp

 // Copyright 2014 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/paint/InlinePainter.h"
 
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutTheme.h"
@@ skipping 13 matching lines @@
     // FIXME: When Skia supports annotation rect covering (https://code.google.com/p/skia/issues/detail?id=3872),
     // this rect may be covered by foreground and descendant drawings. Then we may need a dedicated paint phase.
     if (paintInfo.phase == PaintPhaseForeground && paintInfo.context->printing())
         ObjectPainter(m_layoutInline).addPDFURLRectIfNeeded(paintInfo, paintOffset);
 
     LineBoxListPainter(*m_layoutInline.lineBoxes()).paint(&m_layoutInline, paintInfo, paintOffset);
 }
 
 LayoutRect InlinePainter::outlinePaintRect(const Vector<LayoutRect>& outlineRects, const LayoutPoint& paintOffset) const
 {
-    const ComputedStyle& style = m_layoutInline.styleRef();
-    int outlineOutset;
-    if (style.outlineStyleIsAuto())
-        outlineOutset = GraphicsContext::focusRingOutsetExtent(style.outlineOffset(), style.outlineWidth());
-    else
-        outlineOutset = style.outlineSize();
+    int outlineOutset = m_layoutInline.styleRef().outlineOutset();
     LayoutRect outlineRect;
     for (const LayoutRect& rect : outlineRects) {
         LayoutRect inflatedRect(rect);
         // Inflate the individual rects instead of the union, to avoid losing
         // rects which have degenerate width/height (== isEmpty() true.)
         inflatedRect.inflate(outlineOutset);
         outlineRect.unite(inflatedRect);
     }
     outlineRect.moveBy(paintOffset);
     return outlineRect;
@@ skipping 168 matching lines @@
             pixelSnappedBox.maxX() + outlineWidth,
             pixelSnappedBox.maxY() + outlineWidth,
             BSBottom, outlineColor, outlineStyle,
             outlineWidth,
             outlineWidth,
             antialias);
     }
 }
 
 } // namespace blink