ozone: evdev: Add gamepad support

ui/events/ozone/evdev/event_device_info.cc

Index: ui/events/ozone/evdev/event_device_info.cc
diff --git a/ui/events/ozone/evdev/event_device_info.cc b/ui/events/ozone/evdev/event_device_info.cc
index aa877e0b18ae4f955bec42af2fbf167bef1841dc..81a2df09afd2b156a162a4286a8f23b8ad13bf2a 100644
--- a/ui/events/ozone/evdev/event_device_info.cc
+++ b/ui/events/ozone/evdev/event_device_info.cc
@@ -427,6 +427,21 @@ bool EventDeviceInfo::HasTouchscreen() const {
   return HasAbsXY() && HasDirect();
 }
 
+bool EventDeviceInfo::HasGamepad() const {
+  if (!HasEventType(EV_KEY))
+    return false;
+
+  // If the device has gamepad button, it will be considered
+  // as a gamepad. Note: this WILL have false positives and false negatives. A
+  // concrete solution will use ID_INPUT_JOYSTICK with some patch remving false

[spang, 2017/04/21 05:38:46]

typo: removing

[jkwang, 2017/04/25 21:16:41]

Done.

+  // positives.
+  for (int key = BTN_JOYSTICK; key <= BTN_THUMBR; ++key)

[spang, 2017/05/03 22:00:37]

Please add braces around all multiline blocks. The outer block here has two
lines.

[jkwang, 2017/05/05 00:07:45]

Done.

+    if (HasKeyEvent(key))
+      return true;
+
+  return false;
+}
+
 EventDeviceInfo::LegacyAbsoluteDeviceType
 EventDeviceInfo::ProbeLegacyAbsoluteDevice() const {
   if (!HasAbsXY())