Move viewport actions into an ApplyScroll callback.

third_party/WebKit/Source/core/page/scrolling/ScrollCustomizationCallbacks.cpp

 // Copyright 2015 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/page/scrolling/ScrollCustomizationCallbacks.h"
 
 #include "core/page/scrolling/ScrollStateCallback.h"
 
 namespace blink {
 
 void ScrollCustomizationCallbacks::setDistributeScroll(Element* element, ScrollStateCallback* scrollStateCallback)
 {
     m_distributeScrollCallbacks.set(element, scrollStateCallback);
 }
 
 ScrollStateCallback* ScrollCustomizationCallbacks::getDistributeScroll(Element* element)
 {
     auto it = m_distributeScrollCallbacks.find(element);
     if (it == m_distributeScrollCallbacks.end())
         return nullptr;
     return it->value.get();
 }
 
 void ScrollCustomizationCallbacks::setApplyScroll(Element* element, ScrollStateCallback* scrollStateCallback)
 {
     m_applyScrollCallbacks.set(element, scrollStateCallback);
 }
 
+void ScrollCustomizationCallbacks::removeApplyScroll(Element* element)
+{
+    m_applyScrollCallbacks.remove(element);
+}
+
 ScrollStateCallback* ScrollCustomizationCallbacks::getApplyScroll(Element* element)
 {
     auto it = m_applyScrollCallbacks.find(element);
     if (it == m_applyScrollCallbacks.end())
         return nullptr;
     return it->value.get();
 }
 
 } // namespace blink