MacViews: Overlay Scrollbars with Show/Hide Animations

ui/views/controls/scrollbar/base_scroll_bar.cc

Index: ui/views/controls/scrollbar/base_scroll_bar.cc
diff --git a/ui/views/controls/scrollbar/base_scroll_bar.cc b/ui/views/controls/scrollbar/base_scroll_bar.cc
index 117fe345dffea247bef217e0c73e1210d7ea7b24..24c477499a4b34b8e4c9e00dd60737c3f11703fd 100644
--- a/ui/views/controls/scrollbar/base_scroll_bar.cc
+++ b/ui/views/controls/scrollbar/base_scroll_bar.cc
@@ -128,6 +128,18 @@ void BaseScrollBar::OnThumbStateChanged(CustomButton::ButtonState old_state,
 ///////////////////////////////////////////////////////////////////////////////
 // BaseScrollBar, View implementation:
 
+void BaseScrollBar::Layout() {
+  gfx::Rect thumb_bounds = GetTrackBounds();

[tapted, 2016/02/16 23:32:57]

Yeah - I'm not sure what views/OWNERS will think about doing this.. so, to back
it up, perhaps a comment here like,

// Provide a default implementation that <summarize the layout approach>.

[spqchan, 2016/02/17 00:05:29]

Done.

+  if (IsHorizontal()) {
+    thumb_bounds.set_x(thumb_->x());
+    thumb_bounds.set_width(thumb_->width());
+  } else {
+    thumb_bounds.set_y(thumb_->y());
+    thumb_bounds.set_height(thumb_->height());
+  }
+  thumb_->SetBoundsRect(thumb_bounds);
+}
+
 bool BaseScrollBar::OnMousePressed(const ui::MouseEvent& event) {
   if (event.IsOnlyLeftMouseButton())
     ProcessPressEvent(event);