Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

xfa/fxfa/app/xfa_fontmgr.cpp

Index: xfa/fxfa/app/xfa_fontmgr.cpp
diff --git a/xfa/fxfa/app/xfa_fontmgr.cpp b/xfa/fxfa/app/xfa_fontmgr.cpp
index e915dcbaf78a196e3ed6df2a055e049e5db7da9c..b9cfd6fb284fe3012a28557ab6d06fd7be045db1 100644
--- a/xfa/fxfa/app/xfa_fontmgr.cpp
+++ b/xfa/fxfa/app/xfa_fontmgr.cpp
@@ -1861,7 +1861,8 @@ IFX_Font* CXFA_PDFFontMgr::FindFont(CFX_ByteString strPsName,
   for (const auto& it : *pFontSetDict) {
     const CFX_ByteString& key = it.first;
     CPDF_Object* pObj = it.second;
-    if (!PsNameMatchDRFontName(strPsName, bBold, bItalic, key, bStrictMatch)) {
+    if (!PsNameMatchDRFontName(strPsName.AsByteStringC(), bBold, bItalic, key,
+                               bStrictMatch)) {
       continue;
     }
     CPDF_Object* pDirect = pObj->GetDirect();