Add explicit

src/widgets/tracksliderpopup.h

@@ -39,17 +39,17 @@ class TrackSliderPopup : public QWidget {
   Q_OBJECT
 
 public:
-  TrackSliderPopup(QWidget* parent);
+  explicit TrackSliderPopup(QWidget *parent);
 
-public slots:
+ public slots:
   void SetText(const QString& text);
   void SetSmallText(const QString& small_text);
   void SetPopupPosition(const QPoint& pos);
 
-protected:
+ protected:
   void paintEvent(QPaintEvent*);
 
-private:
+ private:
   static const int kTextMargin;
   static const int kPointLength;
   static const int kPointWidth;
@@ -60,7 +60,7 @@ private:
   void UpdatePosition();
   void SendMouseEventToParent(QMouseEvent* e);
 
-private:
+ private:
   QString text_;
   QString small_text_;
   QPoint pos_;