no need to copy the list of available commands on every call

Change-Id: I131f34a94c998f3dd9fd7a457fb213778040c771

chart2/source/controller/inc/ChartController.hxx

@@ -577,7 +577,7 @@ private:
         const OUString & rCID, eMoveOrResizeType eType, double fAmountLogicX, double fAmountLogicY );
     bool impl_DragDataPoint( const OUString & rCID, double fOffset );
 
-    static std::set< OUString > impl_getAvailableCommands();
+    static const std::set< OUString >& impl_getAvailableCommands();
 
     /** Creates a helper accessibility class that must be initialized via XInitialization.  For
         parameters see

chart2/source/controller/main/ChartController.cxx

@@ -1570,9 +1570,9 @@ void ChartController::impl_initializeAccessible( const uno::Reference< lang::XIn
     }
 }
 
-::std::set< OUString > ChartController::impl_getAvailableCommands()
+const ::std::set< OUString >& ChartController::impl_getAvailableCommands()
 {
-    return {
+    static ::std::set< OUString > s_AvailableCommands {
         // commands for container forward
         "AddDirect",           "NewDoc",                "Open",
         "Save",                "SaveAs",                "SendMail",
@@ -1635,6 +1635,7 @@ void ChartController::impl_initializeAccessible( const uno::Reference< lang::XIn
         "ArrangeRow",
         "StatusBarVisible",
         "ChartElementSelector"};
+    return s_AvailableCommands;
 }
 
 ViewElementListProvider ChartController::getViewElementListProvider()