Make PointerDeviceObserver use ui::InputDeviceEventObserver on X11

chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h

Index: chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h
diff --git a/chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h b/chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h
index 8e9850aca51421036ff449239084a737664bce0e..8170f2bb5cc9f23967af070466238bd52fc23ccc 100644
--- a/chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h
+++ b/chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.h
@@ -7,7 +7,6 @@
 
 #include "base/memory/singleton.h"
 #include "base/observer_list.h"
-#include "chrome/browser/chromeos/device_hierarchy_observer.h"
 #include "ui/events/platform/platform_event_observer.h"
 
 typedef union _XEvent XEvent;
@@ -24,9 +23,6 @@ class XInputHierarchyChangedEventListener : public ui::PlatformEventObserver {
 
   void Stop();
 
-  void AddObserver(DeviceHierarchyObserver* observer);
-  void RemoveObserver(DeviceHierarchyObserver* observer);
-
  private:
   // Defines the delete on exit Singleton traits we like.  Best to have this
   // and const/dest private as recommended for Singletons.
@@ -42,13 +38,8 @@ class XInputHierarchyChangedEventListener : public ui::PlatformEventObserver {
   // Returns true if the event was processed, false otherwise.
   void ProcessedXEvent(XEvent* xevent);
 
-  // Notify observers that a device has been added/removed.
-  void NotifyDeviceHierarchyChanged();
-
   bool stopped_;
 
-  ObserverList<DeviceHierarchyObserver> observer_list_;
-
   DISALLOW_COPY_AND_ASSIGN(XInputHierarchyChangedEventListener);
 };