Refactor Udev device support in Ozone and add a DRM hotplug monitor

ui/events/ozone/device_udev.h

Index: ui/events/ozone/device_udev.h
diff --git a/ui/events/ozone/device_udev.h b/ui/events/ozone/device_udev.h
new file mode 100644
index 0000000000000000000000000000000000000000..717a4f6b88a382370cc40c8c231b6d3cce6099f8
--- /dev/null
+++ b/ui/events/ozone/device_udev.h
@@ -0,0 +1,55 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.

[spang, 2014/04/25 19:50:28]

Can you move ui/events/ozone/*udev* to ui/events/ozone/udev/

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_EVENTS_OZONE_DEVICE_UDEV_H_
+#define UI_EVENTS_OZONE_DEVICE_UDEV_H_
+
+#include <map>
+#include <string>
+
+#include "base/macros.h"
+#include "ui/events/events_export.h"
+#include "ui/events/ozone/monitor_udev.h"
+#include "ui/events/ozone/scoped_udev.h"
+
+namespace ui {
+
+// Device enumerator & monitor using udev.
+//
+// This class enumerates devices attached to the system using udev.
+//
+// It also creates & monitors a udev netlink socket and issues callbacks for
+// any changes to the set of attached devices.
+class EVENTS_EXPORT DeviceUdev {

[spang, 2014/04/25 19:50:28]

Call it "Udev".

+ public:
+  DeviceUdev();
+  ~DeviceUdev();
+
+  // Registers |monitor| for events matching |subsystem|.
+  bool RegisterDeviceMonitor(MonitorUdev* monitor,
+                             const std::string& subsystem);
+
+  // Unregisters |monitor|. Once this is called no further events will be
+  // received by |monitor|.
+  void UnregisterDeviceMonitor(MonitorUdev* monitor);
+
+  // Scan the system for devices matching |subsystem| and calls into |monitor|
+  // for each device found.
+  bool ScanDevices(MonitorUdev* monitor, const std::string& subsystem);
+
+ private:
+  class WatcherUdev;
+
+  // Connection to Udev. This is used by all watchers when registering.
+  scoped_udev udev_;
+
+  // Mapping of listeners to the MessagePump watchers.
+  std::map<MonitorUdev*, WatcherUdev*> monitors_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceUdev);
+};
+
+}  // namespace ui
+
+#endif  // UI_EVENTS_OZONE_DEVICE_UDEV_H_