Use enum class for subtypes of CPDF_Annot.

fpdfsdk/cpdfsdk_interform.cpp

 // Copyright 2016 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 "fpdfsdk/include/cpdfsdk_interform.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 53 matching lines @@
   m_XFAMap.clear();
 #endif  // PDF_ENABLE_XFA
 }
 
 FX_BOOL CPDFSDK_InterForm::HighlightWidgets() {
   return FALSE;
 }
 
 CPDFSDK_Widget* CPDFSDK_InterForm::GetSibling(CPDFSDK_Widget* pWidget,
                                               FX_BOOL bNext) const {
-  std::unique_ptr<CBA_AnnotIterator> pIterator(
-      new CBA_AnnotIterator(pWidget->GetPageView(), "Widget"));
+  std::unique_ptr<CBA_AnnotIterator> pIterator(new CBA_AnnotIterator(
+      pWidget->GetPageView(), CPDF_Annot::Subtype::WIDGET));
 
   if (bNext)
     return static_cast<CPDFSDK_Widget*>(pIterator->GetNextAnnot(pWidget));
 
   return static_cast<CPDFSDK_Widget*>(pIterator->GetPrevAnnot(pWidget));
 }
 
 CPDFSDK_Widget* CPDFSDK_InterForm::GetWidget(CPDF_FormControl* pControl,
                                              bool createIfNeeded) const {
   if (!pControl || !m_pInterForm)
@@ skipping 631 matching lines @@
   }
 }
 
 FX_COLORREF CPDFSDK_InterForm::GetHighlightColor(int nFieldType) {
   if (nFieldType < 0 || nFieldType > kNumFieldTypes)
     return FXSYS_RGB(255, 255, 255);
   if (nFieldType == 0)
     return m_aHighlightColor[0];
   return m_aHighlightColor[nFieldType - 1];
 }