Remove enable/disable wheel gestures setting.

ui/events/blink/input_handler_proxy.cc

 // 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.
 
 #include "ui/events/blink/input_handler_proxy.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 221 matching lines @@
       expect_scroll_update_end_(false),
 #endif
       gesture_scroll_on_impl_thread_(false),
       gesture_pinch_on_impl_thread_(false),
       fling_may_be_active_on_main_thread_(false),
       disallow_horizontal_fling_scroll_(false),
       disallow_vertical_fling_scroll_(false),
       has_fling_animation_started_(false),
       smooth_scroll_enabled_(false),
       uma_latency_reporting_enabled_(base::TimeTicks::IsHighResolution()),
-      use_gesture_events_for_mouse_wheel_(true),
       touch_start_result_(kEventDispositionUndefined) {
   DCHECK(client);
   input_handler_->BindToClient(this);
   cc::ScrollElasticityHelper* scroll_elasticity_helper =
       input_handler_->CreateScrollElasticityHelper();
   if (scroll_elasticity_helper) {
     scroll_elasticity_controller_.reset(
         new InputScrollElasticityController(scroll_elasticity_helper));
   }
 }
@@ skipping 190 matching lines @@
 #endif
 }
 
 InputHandlerProxy::EventDisposition InputHandlerProxy::HandleMouseWheel(
     const WebMouseWheelEvent& wheel_event) {
   // Only call |CancelCurrentFling()| if a fling was active, as it will
   // otherwise disrupt an in-progress touch scroll.
   if (!wheel_event.hasPreciseScrollingDeltas && fling_curve_)
     CancelCurrentFling();
 
-  if (use_gesture_events_for_mouse_wheel_) {
     cc::EventListenerProperties properties =
         input_handler_->GetEventListenerProperties(
             cc::EventListenerClass::kMouseWheel);
     switch (properties) {
       case cc::EventListenerProperties::kPassive:
         return DID_HANDLE_NON_BLOCKING;
       case cc::EventListenerProperties::kBlockingAndPassive:
       case cc::EventListenerProperties::kBlocking:
         return DID_NOT_HANDLE;
       case cc::EventListenerProperties::kNone:
         return DROP_EVENT;
       default:
         NOTREACHED();
         return DROP_EVENT;
     }
-  }
-  return ScrollByMouseWheel(wheel_event);
 }
 
 InputHandlerProxy::EventDisposition InputHandlerProxy::ScrollByMouseWheel(
     const WebMouseWheelEvent& wheel_event) {
   InputHandlerProxy::EventDisposition result = DID_NOT_HANDLE;
   cc::InputHandlerScrollResult scroll_result;
 
   // TODO(ccameron): The rail information should be pushed down into
   // InputHandler.
   gfx::Vector2dF scroll_delta(
@@ skipping 882 matching lines @@
   // is made asynchronously, to minimize divergence between main thread and
   // impl thread event handling paths.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
       base::Bind(&InputScrollElasticityController::ObserveGestureEventAndResult,
                  scroll_elasticity_controller_->GetWeakPtr(), gesture_event,
                  scroll_result));
 }
 
 }  // namespace ui