[not for review - epic CL] Adding Elastic+Momentum+Layered scrolling to views::ScrollView

ui/events/event.h

Index: ui/events/event.h
diff --git a/ui/events/event.h b/ui/events/event.h
index 3d114535b2234482d0983c08ec1db5f8fd5a6cb5..1ee59b2c6271954851408696d03cb341bef980f9 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -984,6 +984,7 @@ class EVENTS_EXPORT ScrollEvent : public MouseEvent {
   float x_offset_ordinal() const { return x_offset_ordinal_; }
   float y_offset_ordinal() const { return y_offset_ordinal_; }
   int finger_count() const { return finger_count_; }
+  int momentum_phase() const { return momentum_phase_; }
 
  private:
   // Potential accelerated offsets.
@@ -994,6 +995,11 @@ class EVENTS_EXPORT ScrollEvent : public MouseEvent {
   float y_offset_ordinal_;
   // Number of fingers on the pad.
   int finger_count_;
+
+  // For non-fling events, provides momentum information (e.g. for the case
+  // where the device provides continuous event updates during a fling).
+  // Bitwise combination of EventMomentumPhase.
+  int momentum_phase_;
 };
 
 class EVENTS_EXPORT GestureEvent : public LocatedEvent {