Expose native, desktop and mobile gesture detection defaults

ui/events/gestures/gesture_recognizer_impl_mac.cc

Index: ui/events/gestures/gesture_recognizer_impl_mac.cc
diff --git a/ui/events/gestures/gesture_recognizer_impl_mac.cc b/ui/events/gestures/gesture_recognizer_impl_mac.cc
index a0d4ba45a9d16ebfa18a261165ce46051b7fd71f..f7f3f60af321b611f61ab85d3d2b957befa91a26 100644
--- a/ui/events/gestures/gesture_recognizer_impl_mac.cc
+++ b/ui/events/gestures/gesture_recognizer_impl_mac.cc
@@ -17,7 +17,7 @@ class GestureRecognizerImplMac : public GestureRecognizer {
   ~GestureRecognizerImplMac() override {}
 
  private:
-  bool ProcessTouchEventPreDispatch(const TouchEvent& event,
+  bool ProcessTouchEventPreDispatch(TouchEvent* event,
                                     GestureConsumer* consumer) override {
     return false;
   }