Store the DC used to initialize wxGCDC, and make it retrievable. This helps with things like wxRenderer.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@53388 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dcgraph.h

@@ -94,6 +94,8 @@ public:
     wxGraphicsContext* GetGraphicsContext() { return m_graphicContext; }
     virtual void SetGraphicsContext( wxGraphicsContext* ctx );
     
+    wxDC* GetBaseDC() { return m_baseDC; }
+    
 protected:
     // the true implementations
     virtual bool DoFloodFill(wxCoord x, wxCoord y, const wxColour& col,
@@ -183,6 +185,7 @@ protected:
     double m_formerScaleX, m_formerScaleY;
 
     wxGraphicsContext* m_graphicContext;
+    wxDC* m_baseDC;
 };
 
 #endif