Expose double-tap platform support via ui::GestureConfiguration

ui/events/gesture_detection/gesture_configuration.h

Index: ui/events/gesture_detection/gesture_configuration.h
diff --git a/ui/events/gesture_detection/gesture_configuration.h b/ui/events/gesture_detection/gesture_configuration.h
index b7ddb2a57e3f05190e44d869367e10934cd2879a..1644eed23df5dc7cffca91f821806d6dfebcc122 100644
--- a/ui/events/gesture_detection/gesture_configuration.h
+++ b/ui/events/gesture_detection/gesture_configuration.h
@@ -24,6 +24,8 @@ class GESTURE_DETECTION_EXPORT GestureConfiguration {
     min_scaling_touch_major_ = default_radius_ * 2;
     min_gesture_bounds_length_ = default_radius_;
   }
+  bool double_tap_enabled() const { return double_tap_enabled_; }
+  void set_double_tap_enabled(bool enabled) { double_tap_enabled_ = enabled; }
   int double_tap_timeout_in_ms() const { return double_tap_timeout_in_ms_; }
   int fling_max_cancel_to_down_time_in_ms() const {
     return fling_max_cancel_to_down_time_in_ms_;
@@ -185,7 +187,10 @@ class GESTURE_DETECTION_EXPORT GestureConfiguration {
   // The default touch radius length used when the only information given
   // by the device is the touch center.
   float default_radius_;
+
+  bool double_tap_enabled_;
   int double_tap_timeout_in_ms_;
+
   // Maximum time between a GestureFlingCancel and a mousedown such that the
   // mousedown is considered associated with the cancel event.
   int fling_max_cancel_to_down_time_in_ms_;