Add opaque "layout item" to widgets for caller's use.

xfa/fwl/core/ifwl_widget.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef XFA_FWL_CORE_IFWL_WIDGET_H_
 #define XFA_FWL_CORE_IFWL_WIDGET_H_
 
 #include <memory>
@@ skipping 59 matching lines @@
   IFWL_Widget* GetOuter();
   uint32_t GetStyles();
   FWL_Error ModifyStyles(uint32_t dwStylesAdded, uint32_t dwStylesRemoved);
   uint32_t GetStylesEx();
   FWL_Error ModifyStylesEx(uint32_t dwStylesExAdded,
                            uint32_t dwStylesExRemoved);
   uint32_t GetStates();
   void SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE);
   uint32_t GetEventKey() const;
   void SetEventKey(uint32_t key);
+  void* GetLayoutItem() const;
+  void SetLayoutItem(void* pItem);
   FWL_Error SetPrivateData(void* module_id,
                            void* pData,
                            PD_CALLBACK_FREEDATA callback);
   void* GetPrivateData(void* module_id);
   FWL_Error Update();
   FWL_Error LockUpdate();
   FWL_Error UnlockUpdate();
   FWL_WidgetHit HitTest(FX_FLOAT fx, FX_FLOAT fy);
   FWL_Error TransformTo(IFWL_Widget* pWidget, FX_FLOAT& fx, FX_FLOAT& fy);
   FWL_Error TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt);
@@ skipping 20 matching lines @@
 
  protected:
   // Takes ownership of |pImpl|.
   void SetImpl(CFWL_WidgetImp* pImpl) { m_pImpl.reset(pImpl); }
 
  private:
   std::unique_ptr<CFWL_WidgetImp> m_pImpl;
 };
 
 #endif  // XFA_FWL_CORE_IFWL_WIDGET_H_