Tiimer based phase info generated for mouse wheel events.

ui/events/blink/web_input_event_traits.cc

Index: ui/events/blink/web_input_event_traits.cc
diff --git a/ui/events/blink/web_input_event_traits.cc b/ui/events/blink/web_input_event_traits.cc
index 706fe9f86e5d44f4037765cd9fe70dd771d63c09..b4f33d13b068203ff2a34dc174e9d663e4d7b7c2 100644
--- a/ui/events/blink/web_input_event_traits.cc
+++ b/ui/events/blink/web_input_event_traits.cc
@@ -220,6 +220,11 @@ bool WebInputEventTraits::ShouldBlockEventStream(
       // Touch move events may be non-blocking but are always explicitly
       // acknowledge by the renderer so they block the event stream.
       return true;
+
+    case WebInputEvent::kMouseWheel:
+      return static_cast<const WebMouseWheelEvent&>(event).dispatch_type ==
+             WebInputEvent::kBlocking;
+
     default:
       return true;
   }