Change the non-blocking event queue to the main thread event queue.

content/renderer/input/render_widget_input_handler.cc

Index: content/renderer/input/render_widget_input_handler.cc
diff --git a/content/renderer/input/render_widget_input_handler.cc b/content/renderer/input/render_widget_input_handler.cc
index 6a0a652a335b31889ffe318323b2789e66718a7b..6694a71583e26d2a15bf3039db7bcd53461922a2 100644
--- a/content/renderer/input/render_widget_input_handler.cc
+++ b/content/renderer/input/render_widget_input_handler.cc
@@ -306,6 +306,8 @@ void RenderWidgetInputHandler::HandleInputEvent(
   }
 
   bool non_blocking =
+      dispatch_type ==
+          InputEventDispatchType::DISPATCH_TYPE_NON_BLOCKING_NOTIFY_MAIN ||
       dispatch_type == InputEventDispatchType::DISPATCH_TYPE_NON_BLOCKING;
   // TODO(dtapuska): Use the input_event.timeStampSeconds as the start
   // ideally this should be when the event was sent by the compositor to the
@@ -399,12 +401,16 @@ void RenderWidgetInputHandler::HandleInputEvent(
   // by reentrant calls for events after the paused one.
   bool no_ack = ignore_ack_for_mouse_move_from_debugger_ &&
                 input_event.type == WebInputEvent::MouseMove;

[tdresser, 2016/03/15 13:41:22]

Could we invert |no_ack| while we're here?

[dtapuska, 2016/03/15 19:46:05]

Done.

-  if (non_blocking) {
+  if (dispatch_type == DISPATCH_TYPE_BLOCKING_NOTIFY_MAIN ||
+      dispatch_type == DISPATCH_TYPE_NON_BLOCKING_NOTIFY_MAIN) {
     // |non_blocking| means it was ack'd already by the InputHandlerProxy
     // so let the delegate know the event has been handled.
-    delegate_->NonBlockingInputEventHandled(input_event.type);
-  } else if (WebInputEventTraits::WillReceiveAckFromRenderer(input_event) &&
-             !no_ack) {
+    delegate_->NotifyInputEventHandled(input_event.type);
+  }
+
+  if ((dispatch_type == DISPATCH_TYPE_BLOCKING ||
+       dispatch_type == DISPATCH_TYPE_BLOCKING_NOTIFY_MAIN) &&
+      !no_ack) {
     scoped_ptr<InputEventAck> response(new InputEventAck(
         input_event.type, ack_result, swap_latency_info,
         std::move(event_overscroll),