Override Do{Freeze,Thaw}() instead of {Freeze,Thaw}() in wxPropGrid code.

{Freeze,Thaw}() themselves are not virtual any more, so overriding them
doesn't really work and it is unnecessary to reimplement the reference
counting already done by the base class anyhow, so override the DoXXX()
versions instead.

Closes #15877.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75640 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/propgrid/propgrid.h

@@ -1073,12 +1073,6 @@ public:
     /** Returns true if any property has been modified by the user. */
     bool IsAnyModified() const { return (m_pState->m_anyModified>0); }
 
-    /**
-        Returns true if updating is frozen (ie Freeze() called but not yet
-        Thaw() ).
-     */
-    bool IsFrozen() const { return (m_frozen>0)?true:false; }
-
     /**
         It is recommended that you call this function any time your code causes
         wxPropertyGrid's top-level parent to change. wxPropertyGrid's OnIdle()
@@ -1559,8 +1553,6 @@ public:
         { return (m_iFlags & flag) ? true : false; }
     void SetInternalFlag( long flag ) { m_iFlags |= flag; }
     void ClearInternalFlag( long flag ) { m_iFlags &= ~(flag); }
-    void IncFrozen() { m_frozen++; }
-    void DecFrozen() { m_frozen--; }
 
     void OnComboItemPaint( const wxPGComboBox* pCb,
                            int item,
@@ -1778,12 +1770,12 @@ public:
     virtual void Refresh( bool eraseBackground = true,
                           const wxRect *rect = (const wxRect *) NULL );
     virtual bool SetFont( const wxFont& font );
-    virtual void Freeze();
     virtual void SetExtraStyle( long exStyle );
-    virtual void Thaw();
     virtual bool Reparent( wxWindowBase *newParent );
 
 protected:
+    virtual void DoThaw();
+
     virtual wxSize DoGetBestSize() const;
 
 #ifndef wxPG_ICON_WIDTH
@@ -1934,9 +1926,6 @@ protected:
     /** 1 if m_latsCaption is also the bottommost caption. */
     //unsigned char       m_lastCaptionBottomnest;
 
-    /** Set to 1 when graphics frozen. */
-    unsigned char       m_frozen;
-
     unsigned char       m_vspacing;
 
     // Used to track when Alt/Ctrl+Key was consumed.