Don't throttle touch events on resent GestureScrollUpdates.

content/browser/renderer_host/input/touch_event_queue.cc

Index: content/browser/renderer_host/input/touch_event_queue.cc
diff --git a/content/browser/renderer_host/input/touch_event_queue.cc b/content/browser/renderer_host/input/touch_event_queue.cc
index 35b1657048ba5635cf1ffbba8c353f8687b94359..aeaf5aeffdf07048ffbb0ecfb46e15f411b853d7 100644
--- a/content/browser/renderer_host/input/touch_event_queue.cc
+++ b/content/browser/renderer_host/input/touch_event_queue.cc
@@ -636,8 +636,10 @@ void TouchEventQueue::OnGestureScrollEvent(
     return;
   }
 
-  if (gesture_event.event.type == blink::WebInputEvent::GestureScrollUpdate)
+  if (gesture_event.event.type == blink::WebInputEvent::GestureScrollUpdate &&
+      gesture_event.event.resendingPluginId == -1) {
     send_touch_events_async_ = true;
+  }
 }
 
 void TouchEventQueue::OnGestureEventAck(
@@ -648,10 +650,13 @@ void TouchEventQueue::OnGestureEventAck(
   // gesture event (or even part of the current sequence).  Worst case, the
   // delay in updating the absorption state will result in minor UI glitches.
   // A valid |pending_async_touchmove_| will be flushed when the next event is
-  // forwarded.
-  if (event.event.type == blink::WebInputEvent::GestureScrollUpdate)
+  // forwarded. Scroll updates that are being resent from a GuestView are
+  // ignored.
+  if (event.event.type == blink::WebInputEvent::GestureScrollUpdate &&
+      event.event.resendingPluginId == -1) {
     send_touch_events_async_ = (ack_result == INPUT_EVENT_ACK_STATE_CONSUMED);
 }

[tdresser, 2015/10/01 13:55:05]

Indentation looks a little off here.

[wjmaclean, 2015/10/01 14:01:03]

Done.

+}
 
 void TouchEventQueue::OnHasTouchEventHandlers(bool has_handlers) {
   DCHECK(!dispatching_touch_ack_);