Rename kAnimatingScrollOnMainThread to kHandlingScrollFromMainThread

ui/events/blink/input_handler_proxy.cc

Index: ui/events/blink/input_handler_proxy.cc
diff --git a/ui/events/blink/input_handler_proxy.cc b/ui/events/blink/input_handler_proxy.cc
index d12cbb0f2839f8c219d0a6c57b338c2cc77444eb..cf495fea0d175d661e741aff3d2ca74943fabe6a 100644
--- a/ui/events/blink/input_handler_proxy.cc
+++ b/ui/events/blink/input_handler_proxy.cc
@@ -427,8 +427,8 @@ void InputHandlerProxy::RecordMainThreadScrollingReasons(
        ++i) {
     unsigned val = 1 << i;
     if (reasons & val) {
-      if (val == cc::MainThreadScrollingReason::kAnimatingScrollOnMainThread) {
-        // We only want to record "animating scroll on main thread" reason if
+      if (val == cc::MainThreadScrollingReason::kHandlingScrollFromMainThread) {
+        // We only want to record "Handling scroll from main thread" reason if
         // it's the only reason. If it's not the only reason, the "real" reason
         // for scrolling on main is something else, and we only want to pay
         // attention to that reason.