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

content/browser/renderer_host/input/input_router_impl.cc

Index: content/browser/renderer_host/input/input_router_impl.cc
diff --git a/content/browser/renderer_host/input/input_router_impl.cc b/content/browser/renderer_host/input/input_router_impl.cc
index 4f00ab21454f89b16da290c120eb65ed6f9dd71e..875dde60ddecbc2bb4d32abf0f12648fce0da115 100644
--- a/content/browser/renderer_host/input/input_router_impl.cc
+++ b/content/browser/renderer_host/input/input_router_impl.cc
@@ -188,6 +188,10 @@ void InputRouterImpl::SendGestureEvent(
       touch_scroll_started_sent_ = true;
       touch_event_queue_->PrependTouchScrollNotification();
     }
+    gesture_event.event.source_touch_event_dispatch_type =
+        touch_event_queue_->SendTouchEventsAsync()

[dtapuska, 2017/05/10 14:49:00]

I don't think we really should query the state here. But instead use the ack
result of the message to determine if we should send the gesture as blocking or
not.

[chongz, 2017/05/24 13:47:09]

Done.

+            ? WebInputEvent::kEventNonBlocking
+            : WebInputEvent::kBlocking;
     touch_event_queue_->OnGestureScrollEvent(gesture_event);
   }