Defer synthetic gesture completions until events have been flushed

content/browser/renderer_host/input/gesture_event_queue.h

Index: content/browser/renderer_host/input/gesture_event_queue.h
diff --git a/content/browser/renderer_host/input/gesture_event_queue.h b/content/browser/renderer_host/input/gesture_event_queue.h
index 4c340701b590b63d03c31986eb437f89da699439..e02d50702cc27208d2664b2bad8c5cca35e7ca5e 100644
--- a/content/browser/renderer_host/input/gesture_event_queue.h
+++ b/content/browser/renderer_host/input/gesture_event_queue.h
@@ -86,11 +86,16 @@ class CONTENT_EXPORT GestureEventQueue {
   // Returns the |TouchpadTapSuppressionController| instance.
   TouchpadTapSuppressionController* GetTouchpadTapSuppressionController();
 
-  // Returns whether there are any gesture event in the queue.
-  bool HasQueuedGestureEvents() const;
-
   void ForwardGestureEvent(const GestureEventWithLatencyInfo& gesture_event);
 
+  // Whether the queue is expecting a gesture event ack.
+  bool ExpectingGestureAck() const;
+
+  bool empty() const {
+    return coalesced_gesture_events_.empty() &&
+           debouncing_deferral_queue_.empty();
+  }
+
   void set_debounce_enabled_for_testing(bool enabled) {
     debounce_enabled_ = enabled;
   }