Fix recursion in handling touch input events acks.

content/browser/renderer_host/input/passthrough_touch_event_queue.h

Index: content/browser/renderer_host/input/passthrough_touch_event_queue.h
diff --git a/content/browser/renderer_host/input/passthrough_touch_event_queue.h b/content/browser/renderer_host/input/passthrough_touch_event_queue.h
index 598e9b86632fd56fb5fe4f2764df083a0f86e5de..cae55abf2450fde3ba8154db656c4273a8f3febe 100644
--- a/content/browser/renderer_host/input/passthrough_touch_event_queue.h
+++ b/content/browser/renderer_host/input/passthrough_touch_event_queue.h
@@ -121,6 +121,8 @@ class CONTENT_EXPORT PassthroughTouchEventQueue : public TouchEventQueue {
   // Whether touch events should be sent as uncancelable or not.
   bool send_touch_events_async_;
 
+  bool processing_acks_;
+
   // Event is saved to compare pointer positions for new touchmove events.
   std::unique_ptr<blink::WebTouchEvent> last_sent_touchevent_;