[Touch Adjustment] Pass primary_pointer_type to WebGestureEvent and disable adjustment for stylus

ui/events/gesture_event_details.h

Index: ui/events/gesture_event_details.h
diff --git a/ui/events/gesture_event_details.h b/ui/events/gesture_event_details.h
index 2b066d56188c5a7ae999492165d8e74b81b8734f..616cd42e8410117a2988212ad068074d4e3a0e14 100644
--- a/ui/events/gesture_event_details.h
+++ b/ui/events/gesture_event_details.h
@@ -45,6 +45,13 @@ struct EVENTS_BASE_EXPORT GestureEventDetails {
     device_type_ = device_type;
   }
 
+  EventPointerType primary_pointer_type() const {
+    return primary_pointer_type_;
+  }
+  void set_primary_pointer_type(EventPointerType primary_pointer_type) {
+    primary_pointer_type_ = primary_pointer_type;
+  }
+
   int touch_points() const { return touch_points_; }
   void set_touch_points(int touch_points) {
     DCHECK_GT(touch_points, 0);
@@ -225,6 +232,10 @@ struct EVENTS_BASE_EXPORT GestureEventDetails {
 
   GestureDeviceType device_type_;
 
+  // |primary_pointer_type_| is used to distinguish between finger-generated and
+  // stylus-generated gestures. This is important for touch adjustment.
+  EventPointerType primary_pointer_type_;
+
   int touch_points_;  // Number of active touch points in the gesture.
 
   // Bounding box is an axis-aligned rectangle that contains all the