Add wxRendererNative::DrawGauge() method.

Add the method with the native implementations for MSW and OS X and a generic
version fallback.

Closes #16406.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77023 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/renderer.h

@@ -349,6 +349,22 @@ public:
     virtual void DrawFocusRect(wxWindow* win, wxDC& dc, const wxRect& rect,
                                int flags = 0) = 0;
 
+    /**
+        Draw a progress bar in the specified rectangle.
+
+        The @a value and @a max arguments determine the part of the progress
+        bar that is drawn as being filled in, @a max must be strictly positive
+        and @a value must be between 0 and @a max.
+
+        @since 3.1.0
+     */
+    virtual void DrawGauge(wxWindow* win,
+                           wxDC& dc,
+                           const wxRect& rect,
+                           int value,
+                           int max,
+                           int flags = 0) = 0;
+
     /**
         Draw the header control button (used, for example, by wxListCtrl).