evdev: Fix infinite loop when devices are unplugged

ui/events/ozone/evdev/event_converter.h

 // Copyright 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 UI_EVENTS_OZONE_EVDEV_EVENT_CONVERTER_H_
 #define UI_EVENTS_OZONE_EVDEV_EVENT_CONVERTER_H_
 
 #include "base/files/file_path.h"
 #include "base/message_loop/message_pump_ozone.h"
 #include "ui/events/event.h"
 #include "ui/events/events_export.h"
 #include "ui/events/ozone/evdev/event_modifiers.h"
 #include "ui/events/ozone/event_converter_ozone.h"
 
 struct input_event;
 
 namespace ui {
 
-class EVENTS_EXPORT EventConverterEvdev : public EventConverterOzone {
+class EVENTS_EXPORT EventConverterEvdev : public EventConverterOzone,
+                                          base::MessagePumpLibevent::Watcher {
  public:
   EventConverterEvdev(int fd,
                       base::FilePath path,
                       EventModifiersEvdev* modifiers);
   virtual ~EventConverterEvdev();
 
   // Overidden from base::MessagePumpLibevent::Watcher.
   virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
   virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 
+  // Overridden from EventConverterOzone.
+  void Start() OVERRIDE;
+  void Stop() OVERRIDE;
+
  protected:
   // Process & dispatch events read from the device.
   virtual void ProcessEvents(const struct input_event* inputs, int count) = 0;
 
   // File descriptor for the /dev/input/event* instance.
   int fd_;
 
   // Path to input device.
   base::FilePath path_;
 
   // Shared modifier state.
   EventModifiersEvdev* modifiers_;
 
+  // Controller for watching the input fd.
+  base::MessagePumpLibevent::FileDescriptorWatcher controller_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(EventConverterEvdev);
 };
 
 }  // namspace ui
 
 #endif  // UI_EVENTS_OZONE_EVDEV_EVENT_CONVERTER_H_