Refactor compositor event handling path to be callback-based

content/renderer/input/input_handler_wrapper.cc

Index: content/renderer/input/input_handler_wrapper.cc
diff --git a/content/renderer/input/input_handler_wrapper.cc b/content/renderer/input/input_handler_wrapper.cc
index 0b0de6cf96e5182fe7820f97caac1fe91f70572e..5050b3833124f7b086d78086444bb00471e2c018 100644
--- a/content/renderer/input/input_handler_wrapper.cc
+++ b/content/renderer/input/input_handler_wrapper.cc
@@ -57,13 +57,15 @@ void InputHandlerWrapper::DidOverscroll(
     const gfx::Vector2dF& accumulated_overscroll,
     const gfx::Vector2dF& latest_overscroll_delta,
     const gfx::Vector2dF& current_fling_velocity,
-    const gfx::PointF& causal_event_viewport_point) {
+    const gfx::PointF& causal_event_viewport_point,
+    bool bundle_ack_with_triggering_event) {
   ui::DidOverscrollParams params;
   params.accumulated_overscroll = accumulated_overscroll;
   params.latest_overscroll_delta = latest_overscroll_delta;
   params.current_fling_velocity = current_fling_velocity;
   params.causal_event_viewport_point = causal_event_viewport_point;
-  input_handler_manager_->DidOverscroll(routing_id_, params);
+  input_handler_manager_->DidOverscroll(routing_id_, params,
+                                        bundle_ack_with_triggering_event);
 }
 
 void InputHandlerWrapper::DidStartFlinging() {