Moving input device hotplug event processing outside of ui/display

ui/events/device_data_manager.cc

Index: ui/events/device_data_manager.cc
diff --git a/ui/events/device_data_manager.cc b/ui/events/device_data_manager.cc
index ba81950b5f11c057c867c706cd691723dad6145f..4a5ca119dd0c784afb1ab3d81292687eee71b4cb 100644
--- a/ui/events/device_data_manager.cc
+++ b/ui/events/device_data_manager.cc
@@ -76,4 +76,16 @@ int64_t DeviceDataManager::GetDisplayForTouchDevice(int touch_device_id) const {
   return gfx::Display::kInvalidDisplayID;
 }
 
+std::vector<TouchscreenDevice> DeviceDataManager::GetTouchscreenDevices() {
+  return std::vector<TouchscreenDevice>();
+}
+
+void DeviceDataManager::AddObserver(InputDeviceEventObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void DeviceDataManager::RemoveObserver(InputDeviceEventObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 }  // namespace ui