Pass wxRect/wxPoint arguments to wxDataViewCustomRenderer by reference.

Instead of passing them by value, use const reference. This change
is safe to do, because these methods' signatures were different in 2.8
anyhow.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67099 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/dataview.h

@@ -1571,7 +1571,7 @@ public:
         Override this to react to double clicks or ENTER.
         This method will only be called in wxDATAVIEW_CELL_ACTIVATABLE mode.
     */
-    virtual bool Activate( wxRect cell,
+    virtual bool Activate( const wxRect& cell,
                            wxDataViewModel* model,
                            const wxDataViewItem & item,
                            unsigned int col );
@@ -1640,8 +1640,8 @@ public:
         Override this to react to a left click.
         This method will only be called in @c wxDATAVIEW_CELL_ACTIVATABLE mode.
     */
-    virtual bool LeftClick( wxPoint cursor,
-                            wxRect cell,
+    virtual bool LeftClick( const wxPoint& cursor,
+                            const wxRect& cell,
                             wxDataViewModel * model,
                             const wxDataViewItem & item,
                             unsigned int col );
@@ -1665,7 +1665,8 @@ public:
     /**
         Override this to start a drag operation. Not yet supported.
     */
-    virtual bool StartDrag(wxPoint cursor, wxRect cell,
+    virtual bool StartDrag(const wxPoint& cursor,
+                           const wxRect& cell,
                            wxDataViewModel* model,
                            const wxDataViewItem & item,
                            unsigned int col);