Provide max gesture bounds and option to ignore touch size during pinch

ui/events/gesture_detection/scale_gesture_detector.h

Index: ui/events/gesture_detection/scale_gesture_detector.h
diff --git a/ui/events/gesture_detection/scale_gesture_detector.h b/ui/events/gesture_detection/scale_gesture_detector.h
index b07f78d5785bcccee2e94ced1cd155d9a7e225ad..563414c41641bcebd60be629900bcd8843b08cde 100644
--- a/ui/events/gesture_detection/scale_gesture_detector.h
+++ b/ui/events/gesture_detection/scale_gesture_detector.h
@@ -31,6 +31,10 @@ class ScaleGestureDetector : public GestureDetector::SimpleGestureListener {
     // Minimum span needed to initiate a scaling gesture (in dips).
     float min_scaling_span;
 
+    // Whether to use touch major values when determining the scale span.
+    // Defaults to false.
+    bool use_touch_major_in_span;
+
     // Whether double-tap drag scaling is enabled.
     bool quick_scale_enabled;
 
@@ -136,12 +140,14 @@ class ScaleGestureDetector : public GestureDetector::SimpleGestureListener {
   float min_span_;
 
   // Bounds for recently seen values.
+  bool use_touch_major_in_span_;
   float touch_upper_;
   float touch_lower_;
   float touch_history_last_accepted_;
   int touch_history_direction_;
   base::TimeTicks touch_history_last_accepted_time_;
   float touch_min_major_;
+  float touch_max_major_;
   float double_tap_focus_x_;
   float double_tap_focus_y_;
   DoubleTapMode double_tap_mode_;