Move ScrollbarManager from core to platform and use as Scrollbar parent

third_party/WebKit/Source/core/input/GestureManager.cpp

 // Copyright 2016 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 "core/input/GestureManager.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/DocumentUserGestureToken.h"
 #include "core/editing/SelectionController.h"
 #include "core/events/GestureEvent.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/frame/VisualViewport.h"
 #include "core/input/EventHandler.h"
 #include "core/input/EventHandlingUtil.h"
 #include "core/input/InputDeviceCapabilities.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/Page.h"
+#include "platform/scroll/ScrollAnimatorBase.h"
 
 namespace blink {
 
 GestureManager::GestureManager(LocalFrame& frame,
                                ScrollManager& scroll_manager,
                                MouseEventManager& mouse_event_manager,
                                PointerEventManager& pointer_event_manager,
                                SelectionController& selection_controller)
     : frame_(frame),
       scroll_manager_(scroll_manager),
@@ skipping 399 matching lines @@
   }
   return WebInputEventResult::kNotHandled;
 }
 
 WTF::Optional<WTF::TimeTicks> GestureManager::GetLastShowPressTimestamp()
     const {
   return last_show_press_timestamp_;
 }
 
 }  // namespace blink