aura: Add back XInputHierarchyChangedEventListener for aura and remove stubs.

chrome/browser/chromeos/xinput_hierarchy_changed_event_listener_gtk.cc

Index: chrome/browser/chromeos/xinput_hierarchy_changed_event_listener_gtk.cc
diff --git a/chrome/browser/chromeos/xinput_hierarchy_changed_event_listener_gtk.cc b/chrome/browser/chromeos/xinput_hierarchy_changed_event_listener_gtk.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d0aeba6aafb2fd6686fd7c885ad20a61a100fa71
--- /dev/null
+++ b/chrome/browser/chromeos/xinput_hierarchy_changed_event_listener_gtk.cc
@@ -0,0 +1,40 @@
+// Copyright (c) 2011 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 "chrome/browser/chromeos/xinput_hierarchy_changed_event_listener.h"
+
+#include <gdk/gdkx.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/XInput2.h>
+
+namespace chromeos {
+
+void XInputHierarchyChangedEventListener::Init() {
+  gdk_window_add_filter(NULL, GdkEventFilter, this);
+}
+
+void XInputHierarchyChangedEventListener::StopImpl() {
+  gdk_window_remove_filter(NULL, GdkEventFilter, this);
+}
+
+// static
+GdkFilterReturn XInputHierarchyChangedEventListener::GdkEventFilter(
+    GdkXEvent* gxevent, GdkEvent* gevent, gpointer data) {
+  XInputHierarchyChangedEventListener* listener =
+      static_cast<XInputHierarchyChangedEventListener*>(data);
+  XEvent* xevent = static_cast<XEvent*>(gxevent);
+
+  if (xevent->xcookie.type != GenericEvent)
+    return GDK_FILTER_CONTINUE;
+
+  if (!XGetEventData(xevent->xgeneric.display, &xevent->xcookie)) {
+    VLOG(1) << "XGetEventData failed";
+    return GDK_FILTER_CONTINUE;
+  }
+  bool processed = listener->ProcessedXEvent(xevent);
+  XFreeEventData(xevent->xgeneric.display, &xevent->xcookie);
+  return  processed ? GDK_FILTER_REMOVE : GDK_FILTER_CONTINUE;
+}
+
+}  // namespace chromeos