XFA: merge patch from CL 733693003, getting rid of more casts

core/src/fpdfapi/fpdf_font/fpdf_font.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 "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_pageobj.h"
 #include "font_int.h"
@@ skipping 210 matching lines @@
             result += (FX_WCHAR)charcode;
         }
     }
     return result;
 }
 CFX_ByteString CPDF_Font::EncodeString(const CFX_WideString& str) const
 {
     CFX_ByteString result;
     int src_len = str.GetLength();
     FX_LPSTR dest_buf = result.GetBuffer(src_len * 2);
-    FX_LPCWSTR src_buf = str;
+    FX_LPCWSTR src_buf = str.c_str();
     int dest_pos = 0;
     for (int src_pos = 0; src_pos < src_len; src_pos ++) {
         FX_DWORD charcode = CharCodeFromUnicode(src_buf[src_pos]);
         dest_pos += AppendChar(dest_buf + dest_pos, charcode);
     }
     result.ReleaseBuffer(dest_pos);
     return result;
 }
 void CPDF_Font::LoadFontDescriptor(CPDF_Dictionary* pFontDesc)
 {
@@ skipping 1519 matching lines @@
 }
 CPDF_Type3Char::~CPDF_Type3Char()
 {
     if (m_pForm) {
         delete m_pForm;
     }
     if (m_pBitmap) {
         delete m_pBitmap;
     }
 }