Move viewport actions into an ApplyScroll callback.

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

 // 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.
 
 #ifndef ScrollCustomizationCallbacks_h
 #define ScrollCustomizationCallbacks_h
 
 #include "core/CoreExport.h"
 #include "core/dom/Element.h"
 #include "platform/heap/Handle.h"
 #include "wtf/HashMap.h"
 
 namespace blink {
 
 class ScrollStateCallback;
 
 class CORE_EXPORT ScrollCustomizationCallbacks : public GarbageCollected<ScrollCustomizationCallbacks> {
     WTF_MAKE_NONCOPYABLE(ScrollCustomizationCallbacks);
 
 public:
     ScrollCustomizationCallbacks() {}
     void setDistributeScroll(Element*, ScrollStateCallback*);
     ScrollStateCallback* getDistributeScroll(Element*);
     void setApplyScroll(Element*, ScrollStateCallback*);
+    void removeApplyScroll(Element*);
     ScrollStateCallback* getApplyScroll(Element*);
 
     DEFINE_INLINE_TRACE()
     {
         visitor->trace(m_applyScrollCallbacks);
         visitor->trace(m_distributeScrollCallbacks);
     };
 
 #if !ENABLE(OILPAN)
     void removeCallbacksForElement(Element*);
 #endif
 
 private:
     using ScrollStateCallbackList = HeapHashMap<WeakMember<Element>, Member<ScrollStateCallback>>;
     ScrollStateCallbackList m_applyScrollCallbacks;
     ScrollStateCallbackList m_distributeScrollCallbacks;
 };
 
 } // namespace blink
 
 #endif // ScrollCustomizationCallbacks_h