Replace virtual with override wherever possible; eliminate needless virtual...

... for functions in final classes.

override is like const -- it's not necessary, but it helps the compiler to
catch mistakes.

There may be some overriding functions not explicitly declared virtual and I did
not identify such cases, in which I might also add override.

src/TrackPanelAx.h

@@ -44,10 +44,10 @@ public:
 #if wxUSE_ACCESSIBILITY
    // Retrieves the address of an IDispatch interface for the specified child.
    // All objects must support this property.
-   virtual wxAccStatus GetChild( int childId, wxAccessible** child );
+   wxAccStatus GetChild(int childId, wxAccessible** child) override;
 
    // Gets the number of children.
-   virtual wxAccStatus GetChildCount(int* childCount);
+   wxAccStatus GetChildCount(int* childCount) override;
 
    // Gets the default action for this object (0) or > 0 (the action for a child).
    // Return wxACC_OK even if there is no action. actionName is the action, or the empty
@@ -55,33 +55,33 @@ public:
    // The retrieved string describes the action that is performed on an object,
    // not what the object does as a result. For example, a toolbar button that prints
    // a document has a default action of "Press" rather than "Prints the current document."
-   virtual wxAccStatus GetDefaultAction( int childId, wxString *actionName );
+   wxAccStatus GetDefaultAction(int childId, wxString *actionName) override;
 
    // Returns the description for this object or a child.
-   virtual wxAccStatus GetDescription( int childId, wxString *description );
+   wxAccStatus GetDescription(int childId, wxString *description) override;
 
    // Gets the window with the keyboard focus.
    // If childId is 0 and child is NULL, no object in
    // this subhierarchy has the focus.
    // If this object has the focus, child should be 'this'.
-   virtual wxAccStatus GetFocus( int *childId, wxAccessible **child );
+   wxAccStatus GetFocus(int *childId, wxAccessible **child) override;
 
    // Returns help text for this object or a child, similar to tooltip text.
-   virtual wxAccStatus GetHelpText( int childId, wxString *helpText );
+   wxAccStatus GetHelpText(int childId, wxString *helpText) override;
 
    // Returns the keyboard shortcut for this object or child.
    // Return e.g. ALT+K
-   virtual wxAccStatus GetKeyboardShortcut( int childId, wxString *shortcut );
+   wxAccStatus GetKeyboardShortcut(int childId, wxString *shortcut) override;
 
    // Returns the rectangle for this object (id = 0) or a child element (id > 0).
    // rect is in screen coordinates.
-   virtual wxAccStatus GetLocation( wxRect& rect, int elementId );
+   wxAccStatus GetLocation(wxRect& rect, int elementId) override;
 
    // Gets the name of the specified object.
-   virtual wxAccStatus GetName( int childId, wxString *name );
+   wxAccStatus GetName(int childId, wxString *name) override;
 
    // Returns a role constant.
-   virtual wxAccStatus GetRole( int childId, wxAccRole *role );
+   wxAccStatus GetRole(int childId, wxAccRole *role) override;
 
    // Gets a variant representing the selected children
    // of this object.
@@ -91,14 +91,14 @@ public:
    // - an integer representing the selected child element,
    //   or 0 if this object is selected (GetType() == wxT("long"))
    // - a "void*" pointer to a wxAccessible child object
-   virtual wxAccStatus GetSelections( wxVariant *selections );
+   wxAccStatus GetSelections(wxVariant *selections) override;
 
    // Returns a state constant.
-   virtual wxAccStatus GetState(int childId, long* state);
+   wxAccStatus GetState(int childId, long* state) override;
 
    // Returns a localized string representing the value for the object
    // or child.
-   virtual wxAccStatus GetValue(int childId, wxString* strValue);
+   wxAccStatus GetValue(int childId, wxString* strValue) override;
 #endif
 
 private: