Fix macOS build

src/widgets/tracksliderslider.cpp

@@ -151,11 +151,11 @@ void TrackSliderSlider::keyPressEvent(QKeyEvent* event) {
   }
 }
 
-#ifndef Q_OS_MACOS
 void TrackSliderSlider::UpdateDeltaTime() {
+#ifndef Q_OS_MACOS
   if (popup_->isVisible()) {
     int delta_seconds = mouse_hover_seconds_ - (value() / kMsecPerSec);
     popup_->SetSmallText(Utilities::PrettyTimeDelta(delta_seconds));
   }
-}
 #endif
+}

src/widgets/tracksliderslider.h

@@ -60,9 +60,7 @@ class TrackSliderSlider : public QSlider {
   void keyPressEvent(QKeyEvent* event);
 
  private slots:
-#ifndef Q_OS_MACOS
   void UpdateDeltaTime();
-#endif
 
  private:
 #ifndef Q_OS_MACOS