ozone: Add some tracing for platform & evdev

ui/events/ozone/event_converter_ozone.cc

Index: ui/events/ozone/event_converter_ozone.cc
diff --git a/ui/events/ozone/event_converter_ozone.cc b/ui/events/ozone/event_converter_ozone.cc
index 2bb6164e80b1e61cd33d4d33e1abcc397f926da6..d624e25cf75c4cdc932a0e40fd39f96acd19e750 100644
--- a/ui/events/ozone/event_converter_ozone.cc
+++ b/ui/events/ozone/event_converter_ozone.cc
@@ -5,6 +5,7 @@
 #include "ui/events/ozone/event_converter_ozone.h"
 
 #include "base/bind.h"
+#include "base/debug/trace_event.h"
 #include "base/message_loop/message_loop.h"
 #include "base/message_loop/message_pump_ozone.h"
 #include "ui/events/event.h"
@@ -12,6 +13,7 @@
 namespace {
 
 void DispatchEventHelper(scoped_ptr<ui::Event> key) {
+  TRACE_EVENT1("ozone", "DispatchEventHelper", "type", key->type());
   base::MessagePumpOzone::Current()->Dispatch(key.get());
 }