Changed DeviceDataManagerX11 to use xinput1 for low resolution scroll devices

ui/events/devices/x11/device_data_manager_x11.cc

Index: ui/events/devices/x11/device_data_manager_x11.cc
diff --git a/ui/events/devices/x11/device_data_manager_x11.cc b/ui/events/devices/x11/device_data_manager_x11.cc
index b0bd0e4b555b9be50f163fda8c074d0c8d342219..b28d459ca4032889bca5561699c735010a6d3108 100644
--- a/ui/events/devices/x11/device_data_manager_x11.cc
+++ b/ui/events/devices/x11/device_data_manager_x11.cc
@@ -773,6 +773,14 @@ void DeviceDataManagerX11::UpdateScrollClassDevice(
     int deviceid) {
   DCHECK(deviceid >= 0 && deviceid < kMaxDeviceNum);
   ScrollInfo& info = scroll_data_[deviceid];
+
+  if ((scroll_class_info->flags & XIScrollFlagNoEmulation) == 0 &&
+      (scroll_class_info->increment == 0.0 ||
+       scroll_class_info->increment == 1.0 ||
+       scroll_class_info->increment == -1.0)) {
+    return;
+  }

[sadrul, 2016/04/19 14:40:50]

Add a comment here. The code could be more readable like so:

  bool x11_sends_legacy_button_events =
      (scroll_class_info->flags & XIScrollFlagNoEmulation) == 0;
  if (x11_sends_legacy_button_events &&
      std::abs(scroll_class_info->increment) <= 1.0) {
    return;
  }

+
   switch (scroll_class_info->scroll_type) {
     case XIScrollTypeVertical:
       info.vertical.number = scroll_class_info->number;