Reland of [VSync Queue] Plug touch ack to gesture events and flush vsync queue if necessary

content/browser/renderer_host/ui_events_helper.cc

Index: content/browser/renderer_host/ui_events_helper.cc
diff --git a/content/browser/renderer_host/ui_events_helper.cc b/content/browser/renderer_host/ui_events_helper.cc
index 8ee439cbff841968a6fab204662e885d87e2eb88..9bfc3bbf55d7814925470dea3aeac5b27191a05e 100644
--- a/content/browser/renderer_host/ui_events_helper.cc
+++ b/content/browser/renderer_host/ui_events_helper.cc
@@ -90,4 +90,14 @@
   return true;
 }
 
+bool InputEventAckStateIsSetNonBlocking(InputEventAckState ack_state) {
+  switch (ack_state) {
+    case INPUT_EVENT_ACK_STATE_SET_NON_BLOCKING:
+    case INPUT_EVENT_ACK_STATE_SET_NON_BLOCKING_DUE_TO_FLING:
+      return true;
+    default:
+      return false;
+  }
+}
+
 }  // namespace content