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

Getting rid of more (FX_LPCWSTR) casts and fixing two bugs revealed by this.

Since casts to FX_LPCWSTR have been shown to hide bugs I tried removing
more of them, targeting those places where a cast was used to force a
conversion from CFX_WideString to FX_LPCWSTR, replacing these casts with
calls to the newly added .c_str() function. This revealed two places
where the cast was hiding a bug -- where ->c_str() was required instead!

This removes ~33 FX_LPCWSTR casts and there are ~31 left, many of which
will go away in some future change.

Also includes this change:

Removing unnecessary casts from wchar_t* to wchar_t*, by various names.

Original patch from Bruce Dawson(brucedawson@chromium.org)

TBR=bo_xu@foxitsoftware.com, tsepez@chromium.org

Review URL: https://codereview.chromium.org/811593007

2 files changed, 4 insertions, 4 deletions

diff --git a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
index 36b6ce2b5b..dd646ca113 100644
--- a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
+++ b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
@@ -228,7 +228,7 @@ 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]);
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
index dd4eeddc17..e431c6ad3c 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
@@ -175,9 +175,9 @@ void FPDF_FileSpec_SetWin32Path(CPDF_Object* pFileSpec, const CFX_WideString& fi
         if (filepath[2] != '\\') {
             result += '/';
         }
-        result += ChangeSlash((FX_LPCWSTR)filepath + 2);
+        result += ChangeSlash(filepath.c_str() + 2);
     } else if (filepath.GetLength() > 1 && filepath[0] == '\\' && filepath[1] == '\\') {
-        result = ChangeSlash((FX_LPCWSTR)filepath + 1);
+        result = ChangeSlash(filepath.c_str() + 1);
     } else {
         result = ChangeSlash(filepath);
     }
@@ -217,7 +217,7 @@ CFX_WideString	FPDF_FileSpec_GetWin32Path(const CPDF_Object* pFileSpec)
         CFX_WideString result;
         result += wsFileName[1];
         result += ':';
-        result += ChangeSlash(((FX_LPCWSTR)wsFileName) + 2);
+        result += ChangeSlash(wsFileName.c_str() + 2);
         return result;
     } else {
         CFX_WideString result;