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..14a0fa15e46c95565c1078570cb380cf13e83e80 100644
--- a/ui/events/ozone/evdev/event_device_info.cc
+++ b/ui/events/ozone/evdev/event_device_info.cc
@@ -251,6 +251,11 @@ void EventDeviceInfo::SetDeviceType(InputDeviceType type) {
   device_type_ = type;
 }
 
+void EventDeviceInfo::SetId(uint16_t vendor_id, uint16_t product_id) {
+  vendor_id_ = vendor_id;
+  product_id_ = product_id;
+}
+
 bool EventDeviceInfo::HasEventType(unsigned int type) const {
   if (type > EV_MAX)
     return false;
@@ -427,6 +432,22 @@ bool EventDeviceInfo::HasTouchscreen() const {
   return HasAbsXY() && HasDirect();
 }
 
+bool EventDeviceInfo::HasGamepad() const {
+  if (!HasEventType(EV_KEY))
+    return false;
+
+  // If the device has gamepad button, and it's not keyboard or tablet, it will
+  // be considered to be a gamepad. Note: this WILL have false positives and
+  // false negatives. A concrete solution will use ID_INPUT_JOYSTICK with some
+  // patch removing false positives.
+  bool support_gamepad_btn = false;
+  for (int key = BTN_JOYSTICK; key <= BTN_THUMBR; ++key)

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

Please brace all multiline blocks such as the outer loop here.

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

Done.

+    if (HasKeyEvent(key))
+      support_gamepad_btn = true;
+
+  return support_gamepad_btn && !HasTablet() && !HasKeyboard();
+}
+
 EventDeviceInfo::LegacyAbsoluteDeviceType
 EventDeviceInfo::ProbeLegacyAbsoluteDevice() const {
   if (!HasAbsXY())