[CSS Shapes] Import and fix polygon shapes reftests

Source/core/rendering/shapes/PolygonShape.cpp

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 82 matching lines @@
 }
 
 static float circleXIntercept(float y, float radius)
 {
     ASSERT(radius > 0);
     return radius * sqrt(1 - (y * y) / (radius * radius));
 }
 
 static FloatShapeInterval clippedCircleXRange(const FloatPoint& center, float radius, float y1, float y2)
 {
-    if (y1 > center.y() + radius || y2 < center.y() - radius)
+    if (y1 >= center.y() + radius || y2 <= center.y() - radius)
         return FloatShapeInterval();
 
     if (center.y() >= y1 && center.y() <= y2)
         return FloatShapeInterval(center.x() - radius, center.x() + radius);
 
     // Clip the circle to the vertical range y1,y2 and return the extent of the clipped circle's
     // projection on the X axis
 
     float xi =  circleXIntercept((y2 < center.y() ? y2 : y1) - center.y(), radius);
     return FloatShapeInterval(center.x() - xi, center.x() + xi);
@@ skipping 22 matching lines @@
     for (unsigned i = 0; i < overlappingEdges.size(); i++) {
         const FloatPolygonEdge& edge = *(overlappingEdges[i]);
         if (edge.maxY() == edge.minY())
             continue;
         if (!shapeMargin()) {
             excludedInterval.unite(OffsetPolygonEdge(edge, FloatSize()).clippedEdgeXRange(y1, y2));
         } else {
             excludedInterval.unite(OffsetPolygonEdge(edge, outwardEdgeNormal(edge) * shapeMargin()).clippedEdgeXRange(y1, y2));
             excludedInterval.unite(OffsetPolygonEdge(edge, inwardEdgeNormal(edge) * shapeMargin()).clippedEdgeXRange(y1, y2));
             excludedInterval.unite(clippedCircleXRange(edge.vertex1(), shapeMargin(), y1, y2));
+            excludedInterval.unite(clippedCircleXRange(edge.vertex2(), shapeMargin(), y1, y2));
         }
     }
 
     if (excludedInterval.isEmpty())
         return LineSegment();
 
     return LineSegment(excludedInterval.x1(), excludedInterval.x2());
 }
 
 void PolygonShape::buildDisplayPaths(DisplayPaths& paths) const
 {
     if (!m_polygon.numberOfVertices())
         return;
     paths.shape.moveTo(m_polygon.vertexAt(0));
     for (size_t i = 1; i < m_polygon.numberOfVertices(); ++i)
         paths.shape.addLineTo(m_polygon.vertexAt(i));
     paths.shape.closeSubpath();
 }
 
 } // namespace blink