Remove enable/disable wheel gestures setting.

ui/events/blink/input_handler_proxy.h

 // Copyright 2013 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.
 
 #ifndef UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_
 #define UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_
 
 #include <memory>
 
 #include "base/containers/hash_tables.h"
@@ skipping 29 matching lines @@
 
   InputHandlerProxy(cc::InputHandler* input_handler,
                     InputHandlerProxyClient* client);
   ~InputHandlerProxy() override;
 
   InputScrollElasticityController* scroll_elasticity_controller() {
     return scroll_elasticity_controller_.get();
   }
 
   void set_smooth_scroll_enabled(bool value) { smooth_scroll_enabled_ = value; }
-  void set_use_gesture_events_for_mouse_wheel(bool value) {
-    use_gesture_events_for_mouse_wheel_ = value;
-  }
 
   enum EventDisposition {
     DID_HANDLE,
     DID_NOT_HANDLE,
     DID_HANDLE_NON_BLOCKING,
     DROP_EVENT
   };
   EventDisposition HandleInputEventWithLatencyInfo(
       const blink::WebInputEvent& event,
       ui::LatencyInfo* latency_info);
@@ skipping 134 matching lines @@
 
   // Non-zero only within the scope of |scrollBy|.
   gfx::Vector2dF current_fling_velocity_;
 
   // Used to animate rubber-band over-scroll effect on Mac.
   std::unique_ptr<InputScrollElasticityController>
       scroll_elasticity_controller_;
 
   bool smooth_scroll_enabled_;
   bool uma_latency_reporting_enabled_;
-  bool use_gesture_events_for_mouse_wheel_;
 
   // The merged result of the last touch start with previous touch starts.
   // This value will get returned for subsequent TouchMove events to allow
   // passive events not to block scrolling.
   int32_t touch_start_result_;
 
   base::TimeTicks last_fling_animate_time_;
 
   DISALLOW_COPY_AND_ASSIGN(InputHandlerProxy);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_