[GeometryInterface] add fromQuad function in DOMQuad.

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

Index: third_party/WebKit/Source/core/dom/DOMQuad.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMQuad.cpp b/third_party/WebKit/Source/core/dom/DOMQuad.cpp
index 1b87a2196f8f044c3a77f6ccbf8b4da5a1cf691a..853e0740e2a90328592cd8861bfa1fd13b31987e 100644
--- a/third_party/WebKit/Source/core/dom/DOMQuad.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMQuad.cpp
@@ -6,6 +6,7 @@
 
 #include "bindings/core/v8/V8ObjectBuilder.h"
 #include "core/dom/DOMPoint.h"
+#include "core/dom/DOMQuadInit.h"
 #include "core/dom/DOMRectInit.h"
 
 namespace blink {
@@ -21,6 +22,13 @@ 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,