Send the pending input event ack before the UpdateRect message

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index cd50991e3b785568574b54c74d85b9582145bc7e..1edd49f3ec3d463a0b46ad2c6d4292b9b9e7d476 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -447,6 +447,9 @@ void RenderWidget::OnHandleInputEvent(const IPC::Message& message) {
 
   bool prevent_default = false;
   if (WebInputEvent::isMouseEventType(input_event->type)) {
+    TRACE_EVENT2("renderer", "HandleMouseMove",

[darin (slow to review), 2011/12/06 23:19:48]

nit: maybe this code would be cleaner with a local variable:

  const WebMouseEvent* mouse_event =
      static_cast<...>(...);
  TRACE_EVENT2(...
               "x", mouse_event->x,
               "y", mouse_event->y);
  prevent_default = WillHandleMouseEvent(*mouse_event);

+                 "x", static_cast<const WebMouseEvent*>(input_event)->x,
+                 "y", static_cast<const WebMouseEvent*>(input_event)->y);
     prevent_default = WillHandleMouseEvent(
         *(static_cast<const WebMouseEvent*>(input_event)));
   }
@@ -839,6 +842,9 @@ void RenderWidget::DoDeferredUpdate() {
   params.flags = next_paint_flags_;
   params.scroll_offset = GetScrollOffset();
 
+  if (pending_input_event_ack_.get())

[darin (slow to review), 2011/12/06 23:19:48]

This probably deserves a comment.

+    Send(pending_input_event_ack_.release());
+
   update_reply_pending_ = true;
   Send(new ViewHostMsg_UpdateRect(routing_id_, params));
   next_paint_flags_ = 0;