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

ui/events/event_utils.cc

Index: ui/events/event_utils.cc
diff --git a/ui/events/event_utils.cc b/ui/events/event_utils.cc
index 2e34a82477e0ed6a591b0e325c4a7d1dd34a4a71..2c3feaad95f2912b6171d45debe8b956e6a198ce 100644
--- a/ui/events/event_utils.cc
+++ b/ui/events/event_utils.cc
@@ -110,6 +110,11 @@ void ComputeEventLatencyOS(const base::NativeEvent& native_event) {
 
   EventType type = EventTypeFromNative(native_event);
   switch (type) {
+#if defined(OS_MACOSX)
+    // ui::MouseWheelEvent is too basic to represent a NSScrollWheel event, so
+    // it is wrapped in a ui::ScrollEvent, but recorded the same in UMA.
+    case ET_SCROLL:
+#endif
     case ET_MOUSEWHEEL:
       UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.MOUSE_WHEEL",
                                   delta.InMicroseconds(), 1, 1000000, 50);