Remove more mouse-specific code

sky/engine/platform/scroll/Scrollbar.cpp

Index: sky/engine/platform/scroll/Scrollbar.cpp
diff --git a/sky/engine/platform/scroll/Scrollbar.cpp b/sky/engine/platform/scroll/Scrollbar.cpp
index de65c077d3733950fd088b312799686dcdfa7418..72ebd85d7fd3245d1adedad3d2781c0f50bf9632 100644
--- a/sky/engine/platform/scroll/Scrollbar.cpp
+++ b/sky/engine/platform/scroll/Scrollbar.cpp
@@ -130,25 +130,12 @@ void Scrollbar::autoscrollTimerFired(Timer<Scrollbar>*)
     autoscrollPressedPart(autoscrollTimerDelay());
 }
 
-static bool thumbUnderMouse(Scrollbar* scrollbar)
-{
-    int thumbPos = scrollbar->trackPosition() + scrollbar->thumbPosition();
-    int thumbLength = scrollbar->thumbLength();
-    return scrollbar->pressedPos() >= thumbPos && scrollbar->pressedPos() < thumbPos + thumbLength;
-}
-
 void Scrollbar::autoscrollPressedPart(double delay)
 {
     // Don't do anything for the thumb or if nothing was pressed.
     if (m_pressedPart == ThumbPart || m_pressedPart == NoPart)
         return;
 
-    // Handle the track.
-    if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
-        setHoveredPart(ThumbPart);
-        return;
-    }
-
     // Handle the arrows and track.
     if (m_scrollableArea && m_scrollableArea->scroll(pressedPartScrollDirection(), pressedPartScrollGranularity()))
         startTimerIfNeeded(delay);
@@ -160,13 +147,6 @@ void Scrollbar::startTimerIfNeeded(double delay)
     if (m_pressedPart == ThumbPart)
         return;
 
-    // Handle the track.  We halt track scrolling once the thumb is level
-    // with us.
-    if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
-        setHoveredPart(ThumbPart);
-        return;
-    }
-
     // We can't scroll if we've hit the beginning or end.
     ScrollDirection dir = pressedPartScrollDirection();
     if (dir == ScrollUp || dir == ScrollLeft) {
@@ -241,19 +221,6 @@ void Scrollbar::setPressedPart(ScrollbarPart part)
     m_pressedPart = part;
 }
 
-void Scrollbar::mouseEntered()
-{
-    if (m_scrollableArea)
-        m_scrollableArea->mouseEnteredScrollbar(this);
-}
-
-void Scrollbar::mouseExited()
-{
-    if (m_scrollableArea)
-        m_scrollableArea->mouseExitedScrollbar(this);
-    setHoveredPart(NoPart);
-}
-
 bool Scrollbar::isOverlayScrollbar() const
 {
     // FIXME(sky): Remove