Track plugin input event latency

ppapi/cpp/private/input_event_private.h

Index: ppapi/cpp/private/input_event_private.h
diff --git a/ppapi/cpp/private/input_event_private.h b/ppapi/cpp/private/input_event_private.h
new file mode 100644
index 0000000000000000000000000000000000000000..98dd75b414fe4c69ec24cb5f05399cca78ff9e70
--- /dev/null
+++ b/ppapi/cpp/private/input_event_private.h
@@ -0,0 +1,23 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef PPAPI_CPP_PRIVATE_INPUT_EVENT_PRIVATE_H_
+#define PPAPI_CPP_PRIVATE_INPUT_EVENT_PRIVATE_H_
+
+#include "ppapi/c/private/ppb_input_event_private.h"
+#include "ppapi/cpp/input_event.h"
+
+namespace pp {
+
+class InputEventPrivate : public InputEvent {
+ public:
+  InputEventPrivate();
+  explicit InputEventPrivate(const InputEvent& event);
+
+  void TraceInputLatency(bool has_damage);
+};
+
+}
+
+#endif   // PPAPI_CPP_PRIVATE_INPUT_EVENT_PRIVATE_H_