[Pinch-to-zoom] Moved scale factor into PinchViewport

Source/platform/geometry/FloatPoint.h

Index: Source/platform/geometry/FloatPoint.h
diff --git a/Source/platform/geometry/FloatPoint.h b/Source/platform/geometry/FloatPoint.h
index 98416e9a7710211eee27182ddfb29a1ffadbe9a4..f042f5741e2ab2b6e73a5a62bd6e9dc922e7188c 100644
--- a/Source/platform/geometry/FloatPoint.h
+++ b/Source/platform/geometry/FloatPoint.h
@@ -123,6 +123,11 @@ public:
         return FloatPoint(std::max(m_x, other.m_x), std::max(m_y, other.m_y));
     }
 
+    FloatPoint shrunkTo(const FloatPoint& other) const
+    {
+        return FloatPoint(std::min(m_x, other.m_x), std::min(m_y, other.m_y));
+    }
+
     FloatPoint transposedPoint() const
     {
         return FloatPoint(m_y, m_x);