ui: Make gfx::Point::Scale() mutate the class, similar to gfx::Rect.

ui/gfx/point_f.h

Index: ui/gfx/point_f.h
diff --git a/ui/gfx/point_f.h b/ui/gfx/point_f.h
index 3e69bd7eab205a7702b07228e15692a54f0b62cb..d9fa4498b12aea6ca9c9f40bbcf2d7ac7fe009e7 100644
--- a/ui/gfx/point_f.h
+++ b/ui/gfx/point_f.h
@@ -20,12 +20,12 @@ class UI_EXPORT PointF : public PointBase<PointF, float, Vector2dF> {
   PointF(float x, float y);
   ~PointF();
 
-  PointF Scale(float scale) const WARN_UNUSED_RESULT {
-    return Scale(scale, scale);
+  void Scale(float scale) {
+    Scale(scale, scale);
   }
 
-  PointF Scale(float x_scale, float y_scale) const WARN_UNUSED_RESULT {
-    return PointF(x() * x_scale, y() * y_scale);
+  void Scale(float x_scale, float y_scale) {
+    SetPoint(x() * x_scale, y() * y_scale);
   }
 
   // Returns a string representation of point.
@@ -56,6 +56,12 @@ inline PointF PointAtOffsetFromOrigin(const Vector2dF& offset_from_origin) {
   return PointF(offset_from_origin.x(), offset_from_origin.y());
 }
 
+UI_EXPORT PointF ScalePoint(const PointF& p, float x_scale, float y_scale);
+
+inline PointF ScalePoint(const PointF& p, float scale) {
+  return ScalePoint(p, scale, scale);
+}
+
 #if !defined(COMPILER_MSVC)
 extern template class PointBase<PointF, float, Vector2dF>;
 #endif