Touchpad scroll latching enabled for Mac behind flag.

content/browser/renderer_host/input/mouse_wheel_event_queue.cc

Index: content/browser/renderer_host/input/mouse_wheel_event_queue.cc
diff --git a/content/browser/renderer_host/input/mouse_wheel_event_queue.cc b/content/browser/renderer_host/input/mouse_wheel_event_queue.cc
index 81d106c54569a85a36e3e301e3c6f5abe04a067a..ccbaa428efa77519362ffca663d7a978a3dc06b5 100644
--- a/content/browser/renderer_host/input/mouse_wheel_event_queue.cc
+++ b/content/browser/renderer_host/input/mouse_wheel_event_queue.cc
@@ -171,10 +171,7 @@ void MouseWheelEventQueue::ProcessMouseWheelAck(
       if (needs_scroll_begin_) {
         // If no GSB has been sent, it will be a non-synthetic GSB.
         SendScrollBegin(scroll_update, false);
-      } else if (has_phase_info) {
-        // If a GSB has been sent, generate a synthetic GSB if we have phase
-        // information. This should be removed once crbug.com/526463 is fully
-        // implemented.

[tdresser, 2016/08/18 13:59:47]

These comments are still relevant, aren't they?

[sahel, 2016/08/18 15:41:56]

Done.

+      } else if (has_phase_info && !enable_scroll_latching_) {
         SendScrollBegin(scroll_update, true);
       }
 
@@ -191,10 +188,8 @@ void MouseWheelEventQueue::ProcessMouseWheelAck(
         // ended.
         SendScrollEnd(scroll_update, false);
       } else if (has_phase_info) {
-        // Generate a synthetic GSE for every update to force hit testing so
-        // that the non-latching behavior is preserved. Remove once
-        // crbug.com/526463 is fully implemented.
-        SendScrollEnd(scroll_update, true);
+        if (!enable_scroll_latching_)
+          SendScrollEnd(scroll_update, true);
       } else {
         scroll_end_timer_.Start(
             FROM_HERE,