Eliminate pinch drift by removing touch radius from span calculation

ui/events/gesture_detection/gesture_configuration_android.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 "ui/events/gesture_detection/gesture_configuration.h"
 
 #include "base/android/build_info.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "ui/gfx/android/view_configuration.h"
@@ skipping 39 matching lines @@
         ViewConfiguration::GetMaximumFlingVelocityInDipsPerSecond());
     set_max_gesture_bounds_length(kMaxGestureBoundsLengthDips);
     set_max_touch_move_in_pixels_for_click(
         ViewConfiguration::GetTouchSlopInDips());
     set_min_fling_velocity(
         ViewConfiguration::GetMinimumFlingVelocityInDipsPerSecond());
     set_min_gesture_bounds_length(kMinGestureBoundsLengthDips);
     set_min_pinch_update_span_delta(0.f);
     set_min_scaling_span_in_pixels(
         ViewConfiguration::GetMinScalingSpanInDips());
-    set_min_scaling_touch_major(
-        ViewConfiguration::GetMinScalingTouchMajorInDips());
     set_show_press_delay_in_ms(ViewConfiguration::GetTapTimeoutInMs());
     set_span_slop(ViewConfiguration::GetTouchSlopInDips() * 2.f);
     set_fling_touchscreen_tap_suppression_enabled(true);
     set_fling_touchpad_tap_suppression_enabled(false);
     set_fling_max_cancel_to_down_time_in_ms(
         ViewConfiguration::GetTapTimeoutInMs());
     set_fling_max_tap_gap_time_in_ms(
         ViewConfiguration::GetLongPressTimeoutInMs());
   }
 
   friend struct base::DefaultSingletonTraits<GestureConfigurationAndroid>;
   DISALLOW_COPY_AND_ASSIGN(GestureConfigurationAndroid);
 };
 
 }  // namespace
 
 // Create a GestureConfigurationAura singleton instance when using Android.
 GestureConfiguration* GestureConfiguration::GetPlatformSpecificInstance() {
   return GestureConfigurationAndroid::GetInstance();
 }
 
 }  // namespace ui