Move ContextMenuAllowedScope to core/input

third_party/WebKit/Source/core/input/ContextMenuAllowedScope.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 ContextMenuAllowedScope_h
 #define ContextMenuAllowedScope_h
 
+#include "core/CoreExport.h"
 #include "platform/wtf/Allocator.h"
 
 namespace blink {
 
-class ContextMenuAllowedScope {
+class CORE_EXPORT ContextMenuAllowedScope {
   STACK_ALLOCATED();
 
  public:
   ContextMenuAllowedScope();
   ~ContextMenuAllowedScope();
 
   static bool IsContextMenuAllowed();
 };
 
 }  // namespace blink
 
 #endif  // ContextMenuAllowedScope_h