Add iterators and unit tests for CPDF_Array class

core/fpdfapi/fpdf_parser/include/cpdf_array.h

 // 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
 
 #ifndef CORE_FPDFAPI_FPDF_PARSER_INCLUDE_CPDF_ARRAY_H_
 #define CORE_FPDFAPI_FPDF_PARSER_INCLUDE_CPDF_ARRAY_H_
 
 #include <vector>
 
 #include "core/fpdfapi/fpdf_parser/include/cpdf_indirect_object_holder.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_object.h"
 #include "core/fxcrt/include/fx_basic.h"
 #include "core/fxcrt/include/fx_coordinates.h"
 
 class CPDF_Array : public CPDF_Object {
  public:
+  using iterator = std::vector<CPDF_Object*>::iterator;
+  using const_iterator = std::vector<CPDF_Object*>::const_iterator;
+
   CPDF_Array();
 
   // CPDF_Object.
   Type GetType() const override;
   CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override;
   CPDF_Array* GetArray() const override;
   bool IsArray() const override;
   CPDF_Array* AsArray() override;
   const CPDF_Array* AsArray() const override;
 
@@ skipping 22 matching lines @@
   void Add(CPDF_Object* pObj, CPDF_IndirectObjectHolder* pObjs = nullptr);
   void AddNumber(FX_FLOAT f);
   void AddInteger(int i);
   void AddString(const CFX_ByteString& str);
   void AddName(const CFX_ByteString& str);
   void AddReference(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
   void AddReference(CPDF_IndirectObjectHolder* pDoc, CPDF_Object* obj) {
     AddReference(pDoc, obj->GetObjNum());
   }
 
+  iterator begin() { return m_Objects.begin(); }
+  iterator end() { return m_Objects.end(); }
+  const_iterator begin() const { return m_Objects.begin(); }
+  const_iterator end() const { return m_Objects.end(); }
+
  protected:
   ~CPDF_Array() override;
 
   std::vector<CPDF_Object*> m_Objects;
 };
 
 #endif  // CORE_FPDFAPI_FPDF_PARSER_INCLUDE_CPDF_ARRAY_H_