QCocoaSystemTrayIcon: Remove unused classes

Both QNSMenu and QSystemTrayIconQMenu aren't referenced anywhere
else, including within qcocoasystemtrayicon.mm, since the QPA
backend was added.

Change-Id: I632c1b230226b2d08afce7f0f0019e9f7c030ba5
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm

@@ -92,7 +92,6 @@
 
 QT_USE_NAMESPACE
 
-@class QT_MANGLE_NAMESPACE(QNSMenu);
 @class QT_MANGLE_NAMESPACE(QNSImageView);
 
 @interface QT_MANGLE_NAMESPACE(QNSStatusItem) : NSObject <NSUserNotificationCenterDelegate>
@@ -123,16 +122,8 @@ QT_USE_NAMESPACE
 -(void)mousePressed:(NSEvent *)mouseEvent button:(Qt::MouseButton)mouseButton;
 @end
 
-@interface QT_MANGLE_NAMESPACE(QNSMenu) : NSMenu <NSMenuDelegate> {
-    QPlatformMenu *qmenu;
-}
--(QPlatformMenu*)menu;
--(id)initWithQMenu:(QPlatformMenu*)qmenu;
-@end
-
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSStatusItem);
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSImageView);
-QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSMenu);
 
 QT_BEGIN_NAMESPACE
 class QSystemTrayIconSys
@@ -447,26 +438,4 @@ QT_END_NAMESPACE
 
 @end
 
-class QSystemTrayIconQMenu : public QPlatformMenu
-{
-public:
-    void doAboutToShow() { emit aboutToShow(); }
-private:
-    QSystemTrayIconQMenu();
-};
-
-@implementation QNSMenu
--(id)initWithQMenu:(QPlatformMenu*)qm {
-    self = [super init];
-    if (self) {
-        self->qmenu = qm;
-        [self setDelegate:self];
-    }
-    return self;
-}
--(QPlatformMenu*)menu {
-    return qmenu;
-}
-@end
-
 #endif // QT_NO_SYSTEMTRAYICON