Ensure that trackpad and trackpoint scrolling works on Windows desktop Aura with legacy trackpad dr…

ui/views/widget/native_widget_win.cc

Index: ui/views/widget/native_widget_win.cc
===================================================================
--- ui/views/widget/native_widget_win.cc	(revision 244237)
+++ ui/views/widget/native_widget_win.cc	(working copy)
@@ -769,7 +769,6 @@
     delegate_->OnMouseEvent(&dpi_event);
     return dpi_event.handled();
   } else if (event.IsMouseEvent()) {
-    CHECK(!event.IsScrollEvent()); // Scroll events don't happen in Windows.
     ui::MouseEvent dpi_event(event);
     if (!(dpi_event.flags() & ui::EF_IS_NON_CLIENT))
       dpi_event.UpdateForRootTransform(scale_transform);
@@ -867,6 +866,11 @@
                                     LPARAM l_param) {
 }
 
+bool NativeWidgetWin::HandleScrollEvent(const ui::ScrollEvent& event) {
+  delegate_->OnScrollEvent(const_cast<ui::ScrollEvent*>(&event));
+  return event.handled();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // NativeWidgetWin, private: