Add CFDE_TxtEdtBuf tests

xfa/fde/cfde_txtedtbuf.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_FDE_CFDE_TXTEDTBUF_H_
 #define XFA_FDE_CFDE_TXTEDTBUF_H_
 
 #include <memory>
 
 #include "core/fxcrt/fx_basic.h"
 #include "core/fxcrt/fx_system.h"
 
 class IFX_MemoryAllocator;
 class IFX_Pause;
 
 class CFDE_TxtEdtBuf {
  public:
   CFDE_TxtEdtBuf();
   ~CFDE_TxtEdtBuf();
 
   int32_t GetChunkSize() const;
   int32_t GetTextLength() const;
   void SetText(const CFX_WideString& wsText);
   CFX_WideString GetText() const;
   FX_WCHAR GetCharByIndex(int32_t nIndex) const;
-  CFX_WideString GetRange(int32_t nBegin, int32_t nCount = -1) const;
+  CFX_WideString GetRange(int32_t nBegin, int32_t nCount) const;
 
-  void Insert(int32_t nPos, const FX_WCHAR* lpText, int32_t nLength = 1);
-  void Delete(int32_t nIndex, int32_t nLength = 1);
-  void Clear(bool bRelease = true);
-
-  bool Optimize(IFX_Pause* pPause = nullptr);
+  void Insert(int32_t nPos, const FX_WCHAR* lpText, int32_t nLength);
+  void Delete(int32_t nIndex, int32_t nLength);
+  void Clear(bool bRelease);
 
  private:
   friend class CFDE_TxtEdtBufIter;
+  friend class CFDE_TxtEdtBufTest;
 
   struct FDE_CHUNKHEADER {
     int32_t nUsed;
     FX_WCHAR wChars[1];
   };
 
   struct FDE_CHUNKPLACE {
     int32_t nChunkIndex;
     int32_t nCharIndex;
   };
 
   void ResetChunkBuffer(int32_t nDefChunkCount, int32_t nChunkSize);
   int32_t CP2Index(const FDE_CHUNKPLACE& cp) const;
   void Index2CP(int32_t nIndex, FDE_CHUNKPLACE& cp) const;
 
+  void SetChunkSizeForTesting(size_t size);
+
   int32_t m_nChunkSize;
 
   int32_t m_nTotal;
   bool m_bChanged;
   CFX_ArrayTemplate<FDE_CHUNKHEADER*> m_Chunks;
   std::unique_ptr<IFX_MemoryAllocator> m_pAllocator;
 };
 
 #endif  // XFA_FDE_CFDE_TXTEDTBUF_H_