Remove IXFA_* interfaces.

xfa/fxfa/app/xfa_ffsignature.cpp

 // 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
 
 #include "xfa/fxfa/app/xfa_ffsignature.h"
 
-#include "xfa/fxfa/app/xfa_ffdoc.h"
 #include "xfa/fxfa/app/xfa_fffield.h"
-#include "xfa/fxfa/app/xfa_ffpageview.h"
 #include "xfa/fxfa/app/xfa_ffwidget.h"
+#include "xfa/include/fxfa/xfa_ffdoc.h"
+#include "xfa/include/fxfa/xfa_ffpageview.h"
 
 CXFA_FFSignature::CXFA_FFSignature(CXFA_FFPageView* pPageView,
                                    CXFA_WidgetAcc* pDataAcc)
     : CXFA_FFField(pPageView, pDataAcc) {}
 CXFA_FFSignature::~CXFA_FFSignature() {}
 FX_BOOL CXFA_FFSignature::LoadWidget() {
   return CXFA_FFField::LoadWidget();
 }
 void CXFA_FFSignature::RenderWidget(CFX_Graphics* pGS,
                                     CFX_Matrix* pMatrix,
@@ skipping 88 matching lines @@
     return FWL_WGTHITTEST_Unknown;
   }
   if (m_rtCaption.Contains(fx, fy)) {
     return FWL_WGTHITTEST_Titlebar;
   }
   return FWL_WGTHITTEST_Client;
 }
 FX_BOOL CXFA_FFSignature::OnSetCursor(FX_FLOAT fx, FX_FLOAT fy) {
   return FALSE;
 }