support SkCanvas as a real lua object



git-svn-id: http://skia.googlecode.com/svn/trunk@9208 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/utils/SkLuaCanvas.h b/include/utils/SkLuaCanvas.h
index b37c38e..e41e58c 100644
--- a/include/utils/SkLuaCanvas.h
+++ b/include/utils/SkLuaCanvas.h
@@ -15,6 +15,8 @@
 
 class SkLuaCanvas : public SkCanvas {
 public:
+    void pushThis();
+
     SkLuaCanvas(int width, int height, lua_State*, const char function[]);
     virtual ~SkLuaCanvas();