Ensure acks are sent for all blocking events.

content/renderer/input/input_event_filter.cc

Index: content/renderer/input/input_event_filter.cc
diff --git a/content/renderer/input/input_event_filter.cc b/content/renderer/input/input_event_filter.cc
index 8fbe0f9de23f5d00634c55a41b20019f8cf847b1..7f7b09fa6c3f5ff2f696153df29996a5ff82dc0c 100644
--- a/content/renderer/input/input_event_filter.cc
+++ b/content/renderer/input/input_event_filter.cc
@@ -101,15 +101,15 @@ void InputEventFilter::DidStopFlinging(int routing_id) {
   SendMessage(base::WrapUnique(new InputHostMsg_DidStopFlinging(routing_id)));
 }
 
-void InputEventFilter::NotifyInputEventHandled(
-    int routing_id,
-    blink::WebInputEvent::Type type) {
+void InputEventFilter::NotifyInputEventHandled(int routing_id,
+                                               blink::WebInputEvent::Type type,
+                                               InputEventAckState ack_result) {
   DCHECK(target_task_runner_->BelongsToCurrentThread());
   RouteQueueMap::iterator iter = route_queues_.find(routing_id);
   if (iter == route_queues_.end() || !iter->second)
     return;
 
-  iter->second->EventHandled(type);
+  iter->second->EventHandled(type, ack_result);
 }
 
 void InputEventFilter::OnFilterAdded(IPC::Sender* sender) {
@@ -243,4 +243,13 @@ void InputEventFilter::SendEventToMainThread(
   main_task_runner_->PostTask(FROM_HERE, base::Bind(main_listener_, new_msg));
 }
 
+void InputEventFilter::SendInputEventAck(int routing_id,
+                                         blink::WebInputEvent::Type type,
+                                         InputEventAckState ack_result,
+                                         uint32_t touch_event_id) {
+  InputEventAck ack(type, ack_result, touch_event_id);
+  SendMessage(std::unique_ptr<IPC::Message>(
+      new InputHostMsg_HandleInputEvent_ACK(routing_id, ack)));
+}
+
 }  // namespace content