Forgot to update this enhancement from last weekend

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@8852 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/os2/bitmap.h

@@ -55,6 +55,7 @@ public:
 
     wxDC*                           m_pSelectedInto;
     HPS                             m_hPresentationSpace;
+    LONG                            m_lId;
 
     // optional mask for transparent drawing
     wxMask*                         m_pBitmapMask;
@@ -210,6 +211,10 @@ public:
     // An OS/2 version that probably doesn't do anything like the msw version
     wxBitmap GetBitmapForDC(wxDC& rDc) const;
 
+    inline LONG GetId() const
+      { return (GetBitmapData() ? GetBitmapData()->m_lId : 0L); }
+
+
 protected:
     // common part of all ctors
     void Init();