[cluttermm] Size: Use _CUSTOM_DEFAULT_CTOR to avoid ambiguous constructor calls.

[Murray Cumming <murrayc src gnome org>]

commit f4e2448b0a19ad02ce26809ec0c68c49ebe44e1d
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Mar 21 11:04:08 2014 +0100

    Size: Use _CUSTOM_DEFAULT_CTOR to avoid ambiguous constructor calls.

 clutter/src/size.hg |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/clutter/src/size.hg b/clutter/src/size.hg
index 129c749..7f7d33c 100644
--- a/clutter/src/size.hg
+++ b/clutter/src/size.hg
@@ -30,6 +30,7 @@ class Size
 {
   _CLASS_BOXEDTYPE_STATIC(Size, ClutterSize,  clutter_size_alloc, clutter_size_copy, clutter_size_free)
 public:
+  _CUSTOM_DEFAULT_CTOR
   explicit Size(float width = 0, float height = 0);
 
   //Prevents ambiguous calls to Size(ClutterSize*, bool)