Remove use_aura build arg.

ui/events/gesture_detection/gesture_configuration_aura.cc

Index: ui/events/gesture_detection/gesture_configuration_aura.cc
diff --git a/ui/events/gesture_detection/gesture_configuration_aura.cc b/ui/events/gesture_detection/gesture_configuration_aura.cc
deleted file mode 100644
index df4bcf471ac6819dcf6abce11565472647257631..0000000000000000000000000000000000000000
--- a/ui/events/gesture_detection/gesture_configuration_aura.cc
+++ /dev/null
@@ -1,52 +0,0 @@
-// 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/command_line.h"
-#include "base/memory/singleton.h"
-#include "ui/events/event_switches.h"
-
-namespace ui {
-namespace {
-
-class GestureConfigurationAura : public GestureConfiguration {
- public:
-  ~GestureConfigurationAura() override {
-  }
-
-  static GestureConfigurationAura* GetInstance() {
-    return Singleton<GestureConfigurationAura>::get();
-  }
-
- private:
-  GestureConfigurationAura() : GestureConfiguration() {
-    set_double_tap_enabled(false);
-    set_double_tap_timeout_in_ms(semi_long_press_time_in_ms());
-    set_gesture_begin_end_types_enabled(true);
-    set_min_gesture_bounds_length(default_radius());
-    set_min_pinch_update_span_delta(
-        base::CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kCompensateForUnstablePinchZoom)
-            ? 5
-            : 0);
-    set_min_scaling_touch_major(default_radius() * 2);
-    set_velocity_tracker_strategy(VelocityTracker::Strategy::LSQ2_RESTRICTED);
-    set_span_slop(max_touch_move_in_pixels_for_click() * 2);
-    set_swipe_enabled(true);
-    set_two_finger_tap_enabled(true);
-  }
-
-  friend struct DefaultSingletonTraits<GestureConfigurationAura>;
-  DISALLOW_COPY_AND_ASSIGN(GestureConfigurationAura);
-};
-
-}  // namespace
-
-// Create a GestureConfigurationAura singleton instance when using aura.
-GestureConfiguration* GestureConfiguration::GetPlatformSpecificInstance() {
-  return GestureConfigurationAura::GetInstance();
-}
-
-}  // namespace ui