Add PlatformWindow/Event related code for Ozone X11.

ui/events/platform/x11/x11_event_source_linux.cc

Index: ui/events/platform/x11/x11_event_source_linux.cc
diff --git a/ui/events/platform/x11/x11_event_source_linux.cc b/ui/events/platform/x11/x11_event_source_linux.cc
new file mode 100644
index 0000000000000000000000000000000000000000..629393f3b60f773101848c86c868f74bec311010
--- /dev/null
+++ b/ui/events/platform/x11/x11_event_source_linux.cc
@@ -0,0 +1,16 @@
+// Copyright 2016 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.
+
+#include "ui/events/platform/x11/x11_event_source.h"
+
+namespace ui {
+
+uint32_t X11EventSource::DispatchEvent(base::NativeEvent native_event) {
+  XEvent* xevent = static_cast<XEvent*>(native_event);
+  uint32_t action = PlatformEventSource::DispatchEvent(xevent);
+  PostDispatchEvent(xevent);
+  return action;
+}
+
+}  // namespace ui