Implement FloatRect::squaredDistanceTo function

third_party/WebKit/Source/platform/geometry/FloatRect.cpp

Index: third_party/WebKit/Source/platform/geometry/FloatRect.cpp
diff --git a/third_party/WebKit/Source/platform/geometry/FloatRect.cpp b/third_party/WebKit/Source/platform/geometry/FloatRect.cpp
index 13c4b815ff075a05fdba414b6d9e395ed78e6e63..7b5b79a5a6c35f7c7f5115c045b985d1d322d00b 100644
--- a/third_party/WebKit/Source/platform/geometry/FloatRect.cpp
+++ b/third_party/WebKit/Source/platform/geometry/FloatRect.cpp
@@ -171,6 +171,14 @@ void FloatRect::scale(float sx, float sy)
     m_size.setHeight(height() * sy);
 }
 
+float FloatRect::squaredDistanceTo(const FloatPoint& point) const
+{
+    FloatPoint closestPoint;
+    closestPoint.setX(clampTo<float>(point.x(), x(), maxX()));
+    closestPoint.setY(clampTo<float>(point.y(), y(), maxY()));
+    return (point - closestPoint).diagonalLengthSquared();
+}
+
 FloatRect unionRect(const Vector<FloatRect>& rects)
 {
     FloatRect result;