Ensure that info bar message uses the set font/colours in wxGTK.

Propagate the font and colours set on wxInfoBar window itself to its label in
the native GTK implementation.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62286 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/infobar.h

@@ -55,6 +55,7 @@ public:
 
 protected:
     virtual bool GTKShouldConnectSizeRequest() const { return false; }
+    virtual void DoApplyWidgetStyle(GtkRcStyle *style);
 
 private:
     void Init() { m_impl = NULL; }

src/gtk/infobar.cpp

@@ -266,4 +266,12 @@ void wxInfoBar::RemoveButton(wxWindowID btnid)
     wxFAIL_MSG( wxString::Format("button with id %d not found", btnid) );
 }
 
+void wxInfoBar::DoApplyWidgetStyle(GtkRcStyle *style)
+{
+    wxInfoBarGeneric::DoApplyWidgetStyle(style);
+
+    if ( UseNative() )
+        gtk_widget_modify_style(m_impl->m_label, style);
+}
+
 #endif // wxUSE_INFOBAR