[GeometryInterface] add fromQuad function in DOMQuad.

third_party/WebKit/Source/core/dom/DOMQuad.cpp

 // Copyright 2016 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 "core/dom/DOMQuad.h"
 
 #include "bindings/core/v8/V8ObjectBuilder.h"
 #include "core/dom/DOMPoint.h"
+#include "core/dom/DOMQuadInit.h"
 #include "core/dom/DOMRectInit.h"
 
 namespace blink {
 
 DOMQuad* DOMQuad::create(const DOMPointInit& p1,
                          const DOMPointInit& p2,
                          const DOMPointInit& p3,
                          const DOMPointInit& p4) {
   return new DOMQuad(p1, p2, p3, p4);
 }
 
 DOMQuad* DOMQuad::fromRect(const DOMRectInit& other) {
   return new DOMQuad(other.x(), other.y(), other.width(), other.height());
 }
 
+DOMQuad* DOMQuad::fromQuad(const DOMQuadInit& other) {
+  return new DOMQuad(other.hasP1() ? other.p1() : DOMPointInit(),
+                     other.hasP2() ? other.p2() : DOMPointInit(),
+                     other.hasP3() ? other.p3() : DOMPointInit(),
+                     other.hasP3() ? other.p4() : DOMPointInit());
+}
+
 DOMQuad::DOMQuad(const DOMPointInit& p1,
                  const DOMPointInit& p2,
                  const DOMPointInit& p3,
                  const DOMPointInit& p4)
     : m_p1(DOMPoint::fromPoint(p1)),
       m_p2(DOMPoint::fromPoint(p2)),
       m_p3(DOMPoint::fromPoint(p3)),
       m_p4(DOMPoint::fromPoint(p4)) {}
 
 DOMQuad::DOMQuad(double x, double y, double width, double height)
     : m_p1(DOMPoint::create(x, y, 0, 1)),
       m_p2(DOMPoint::create(x + width, y, 0, 1)),
       m_p3(DOMPoint::create(x + width, y + height, 0, 1)),
       m_p4(DOMPoint::create(x, y + height, 0, 1)) {}
 
 ScriptValue DOMQuad::toJSONForBinding(ScriptState* scriptState) const {
   V8ObjectBuilder result(scriptState);
   result.add("p1", p1());
   result.add("p2", p2());
   result.add("p3", p3());
   result.add("p4", p4());
   return result.scriptValue();
 }
 
 }  // namespace blink