MacViews: Send Mac scrollWheel NSEvents as ui::ET_SCROLL (ui::ScrollEvent).

ui/events/x/events_x.cc

Index: ui/events/x/events_x.cc
diff --git a/ui/events/x/events_x.cc b/ui/events/x/events_x.cc
index 1e84640d76dbd1b0104cb35ea391a43445442adf..5473615767a1532eb84d3c5591e9e365ae853b6c 100644
--- a/ui/events/x/events_x.cc
+++ b/ui/events/x/events_x.cc
@@ -168,7 +168,8 @@ bool GetScrollOffsets(const base::NativeEvent& native_event,
                       float* y_offset,
                       float* x_offset_ordinal,
                       float* y_offset_ordinal,
-                      int* finger_count) {
+                      int* finger_count,
+                      EventMomentumPhase* momentum_phase) {
   return GetScrollOffsetsFromXEvent(*native_event, x_offset, y_offset,
                                     x_offset_ordinal, y_offset_ordinal,
                                     finger_count);