[GeometryInterface] add getBounds function in DOMQaud.

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 853e0740e2a90328592cd8861bfa1fd13b31987e..d380b3f13892e91a2412bba18f46f9bec931f747 100644
--- a/third_party/WebKit/Source/core/dom/DOMQuad.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMQuad.cpp
@@ -7,6 +7,7 @@
 #include "bindings/core/v8/V8ObjectBuilder.h"
 #include "core/dom/DOMPoint.h"
 #include "core/dom/DOMQuadInit.h"
+#include "core/dom/DOMRect.h"
 #include "core/dom/DOMRectInit.h"
 
 namespace blink {
@@ -29,6 +30,22 @@ DOMQuad* DOMQuad::fromQuad(const DOMQuadInit& other) {
                      other.hasP3() ? other.p4() : DOMPointInit());
 }
 
+DOMRect* DOMQuad::getBounds() {
+  double left = std::min(p1()->x(), p2()->x());

[zino, 2017/02/13 15:23:18]

This might be inefficiency. We should cache the bounds value and
just return it when calling getBounds().

+  left = std::min(left, p3()->x());
+  left = std::min(left, p4()->x());
+  double top = std::min(p1()->y(), p2()->y());
+  top = std::min(top, p3()->y());
+  top = std::min(top, p4()->y());
+  double right = std::max(p1()->x(), p2()->x());
+  right = std::max(right, p3()->x());
+  right = std::max(right, p4()->x());
+  double bottom = std::max(p1()->y(), p2()->y());
+  bottom = std::max(bottom, p3()->y());
+  bottom = std::max(bottom, p4()->y());
+  return DOMRect::create(left, top, right - left, bottom - top);
+}
+
 DOMQuad::DOMQuad(const DOMPointInit& p1,
                  const DOMPointInit& p2,
                  const DOMPointInit& p3,