Fix offset outside bounds warning on GCC

core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp

Index: core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
diff --git a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
index 62be48818b1365b13baf87cea8ce5b258412dcaf..f5464cc21e0d709ad53aa013c9797e4cb5542df8 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.cpp
@@ -471,7 +471,7 @@ CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjectHolder* pObjList,
       if (!pObj)
         continue;
 
-      CFX_ByteStringC keyNoSlash(key.c_str() + 1, key.GetLength() - 1);
+      CFX_ByteStringC keyNoSlash(key.raw_str() + 1, key.GetLength() - 1);
       pDict->SetAt(keyNoSlash, pObj);
     }