Eliminate pinch drift by removing touch radius from span calculation

ui/events/gesture_detection/gesture_configuration.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "build/build_config.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
 
 namespace ui {
 namespace {
 
@@ skipping 35 matching lines @@
       max_time_between_double_click_in_ms_(700),
       max_touch_down_duration_for_click_in_ms_(800),
       max_touch_move_in_pixels_for_click_(15),
       min_distance_for_pinch_scroll_in_pixels_(20),
       min_fling_velocity_(30.0f),
       min_gesture_bounds_length_(0),
       min_pinch_update_span_delta_(0),
       // If this is too small, we currently can get single finger pinch zoom.
       // See crbug.com/357237 for details.
       min_scaling_span_in_pixels_(125),
-      // The default value of min_scaling_touch_major_ is 2 * default_radius_.
-      min_scaling_touch_major_(50),
       min_swipe_velocity_(20),
       // TODO(jdduke): Disable and remove entirely when issues with intermittent
       // scroll end detection on the Pixel are resolved, crbug.com/353702.
 #if defined(OS_CHROMEOS)
       scroll_debounce_interval_in_ms_(30),
 #else
       scroll_debounce_interval_in_ms_(0),
 #endif
       semi_long_press_time_in_ms_(400),
       show_press_delay_in_ms_(150),
       // The default value of span_slop_ is
       // 2 * max_touch_move_in_pixels_for_click_.
       span_slop_(30),
       swipe_enabled_(false),
       tab_scrub_activation_delay_in_ms_(200),
       two_finger_tap_enabled_(false),
       velocity_tracker_strategy_(VelocityTracker::Strategy::STRATEGY_DEFAULT) {
 }
 
 GestureConfiguration::~GestureConfiguration() {
 }
 
 }  // namespace ui