Touchpad scroll latching enabled for Mac behind flag.

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 99d5af9e96c2bd2ace893cb36b968f3f9a6f5ac9..55b10e55193191b9706dcb358930b7804adf30d4 100644
--- a/content/browser/renderer_host/input/mouse_wheel_event_queue.h
+++ b/content/browser/renderer_host/input/mouse_wheel_event_queue.h
@@ -80,7 +80,9 @@ class CONTENT_EXPORT MouseWheelEventQueue {
 
  private:
   void TryForwardNextEventToRenderer();
-  void SendScrollEnd(blink::WebGestureEvent update_event, bool synthetic);
+  void SendScrollEnd(blink::WebGestureEvent update_event,
+                     bool synthetic,
+                     bool fling_might_happen_next);

[tdresser, 2016/11/14 16:02:29]

Can we be consistent, and call this may_precede_fling as well?

[sahel, 2016/11/18 16:13:58]

Done.

   void SendScrollBegin(const blink::WebGestureEvent& gesture_update,
                        bool synthetic);
 
@@ -103,6 +105,8 @@ class CONTENT_EXPORT MouseWheelEventQueue {
   int64_t scroll_transaction_ms_;
   blink::WebGestureDevice scrolling_device_;
 
+  blink::WebGestureEvent last_scroll_update_;
+
   DISALLOW_COPY_AND_ASSIGN(MouseWheelEventQueue);
 };