Code change to avoid signed/unsigned mismatch warnings

fpdfsdk/javascript/Field.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 "fpdfsdk/javascript/Field.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 996 matching lines @@
       GetFormFields(pDocument, swFieldName);
 
   for (CPDF_FormField* pFormField : FieldArray) {
     int nFieldType = pFormField->GetFieldType();
     if (nFieldType == FIELDTYPE_COMBOBOX || nFieldType == FIELDTYPE_LISTBOX) {
       uint32_t dwFieldFlags = pFormField->GetFieldFlags();
       pFormField->ClearSelection(TRUE);
       for (size_t i = 0; i < array.size(); ++i) {
         if (i != 0 && !(dwFieldFlags & (1 << 21)))
           break;
-        if (array[i] < pFormField->CountOptions() &&
+        if (array[i] < static_cast<uint32_t>(pFormField->CountOptions()) &&
             !pFormField->IsItemSelected(array[i])) {
           pFormField->SetItemSelection(array[i], TRUE);
         }
       }
       UpdateFormField(pDocument, pFormField, TRUE, TRUE, TRUE);
     }
   }
 }
 
 FX_BOOL Field::defaultStyle(IJS_Context* cc,
@@ skipping 2524 matching lines @@
   }
 }
 
 void Field::AddField(CPDFSDK_Document* pDocument,
                      int nPageIndex,
                      int nFieldType,
                      const CFX_WideString& sName,
                      const CFX_FloatRect& rcCoords) {
   // Not supported.
 }