Animated scroll shouldn't consume unhandled scrolls for OOPIFs.

content/browser/renderer_host/input/mouse_wheel_event_queue.h

Index: content/browser/renderer_host/input/mouse_wheel_event_queue.h
diff --git a/content/browser/renderer_host/input/mouse_wheel_event_queue.h b/content/browser/renderer_host/input/mouse_wheel_event_queue.h
index 1f465b5051cd8f5d5218b4862d2c09276505f416..81818aedd508ee68ba88e7f6c11714c34d081ac1 100644
--- a/content/browser/renderer_host/input/mouse_wheel_event_queue.h
+++ b/content/browser/renderer_host/input/mouse_wheel_event_queue.h
@@ -37,6 +37,7 @@ class CONTENT_EXPORT MouseWheelEventQueueClient {
       const ui::LatencyInfo& latency_info) = 0;
   virtual void OnMouseWheelEventAck(const MouseWheelEventWithLatencyInfo& event,
                                     InputEventAckState ack_result) = 0;
+  virtual bool is_in_gesture_scroll() = 0;
 };
 
 // A queue for throttling and coalescing mouse wheel events.
@@ -90,13 +91,6 @@ class CONTENT_EXPORT MouseWheelEventQueue {
   std::deque<std::unique_ptr<QueuedWebMouseWheelEvent>> wheel_queue_;
   std::unique_ptr<QueuedWebMouseWheelEvent> event_sent_for_gesture_ack_;
 
-  // True if a non-synthetic GSB needs to be sent before a GSU is sent.
-  bool needs_scroll_begin_;
-
-  // True if a non-synthetic GSE needs to be sent because a non-synthetic
-  // GSB has been sent in the past.
-  bool needs_scroll_end_;
-
   // True if the touchpad and wheel scroll latching is enabled.
   bool enable_scroll_latching_;