adapt code to last round of discussions

Change-Id: Id0d2bae2a232f80ebe46cb55602c15c57b074e87

chart2/source/controller/sidebar/ChartElementsPanel.cxx

@@ -271,8 +271,8 @@ ChartElementsPanel::ChartElementsPanel(
     get(mpCBLegend,  "checkbutton_legend");
     get(mpCBGridVertical,  "checkbutton_gridline_vertical");
     get(mpCBGridHorizontal,  "checkbutton_gridline_horizontal");
-    get(mpCBShowLabel,  "checkbutton_label");
-    get(mpCBTrendline,  "checkbutton_trendline");
+
+    Initialize();
 }
 
 ChartElementsPanel::~ChartElementsPanel()
@@ -300,8 +300,6 @@ void ChartElementsPanel::dispose()
     mpCBLegend.clear();
     mpCBGridVertical.clear();
     mpCBGridHorizontal.clear();
-    mpCBShowLabel.clear();
-    mpCBTrendline.clear();
 
     PanelLayout::dispose();
 }

chart2/source/controller/sidebar/ChartElementsPanel.hxx

@@ -87,8 +87,6 @@ private:
     VclPtr<CheckBox> mpCBLegend;
     VclPtr<CheckBox> mpCBGridVertical;
     VclPtr<CheckBox> mpCBGridHorizontal;
-    VclPtr<CheckBox> mpCBShowLabel;
-    VclPtr<CheckBox> mpCBTrendline;
 
     css::uno::Reference<css::frame::XFrame> mxFrame;
     ::sfx2::sidebar::EnumContext            maContext;