ui: Make gfx::Size::Scale() mutate the class. Add gfx::ScaleSize() similar to Rect/Point.

content/renderer/disambiguation_popup_helper.cc

Index: content/renderer/disambiguation_popup_helper.cc
diff --git a/content/renderer/disambiguation_popup_helper.cc b/content/renderer/disambiguation_popup_helper.cc
index 1399518701b56cfc6bf932d8a641304802cc14d8..75bb913551ebdafefee50b09ff816e275768f734 100644
--- a/content/renderer/disambiguation_popup_helper.cc
+++ b/content/renderer/disambiguation_popup_helper.cc
@@ -66,7 +66,7 @@ gfx::Rect CropZoomArea(const gfx::Rect& zoom_rect,
   gfx::Size max_size = viewport_size;
   max_size.Enlarge(-2 * kDisambiguationPopupBoundsMargin,
                    -2 * kDisambiguationPopupBoundsMargin);
-  max_size = ToCeiledSize(max_size.Scale(1.0 / scale));
+  max_size = ToCeiledSize(ScaleSize(max_size, 1.0 / scale));
 
   int left = touch_point.x() - zoom_rect.x();
   int right = zoom_rect.right() - touch_point.x();