Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

core/fpdfdoc/doc_basic.cpp

Index: core/fpdfdoc/doc_basic.cpp
diff --git a/core/fpdfdoc/doc_basic.cpp b/core/fpdfdoc/doc_basic.cpp
index c711709e73aea5f2f32525eec9130deebee63965..0c7f89540550f861c3afec36183ba859c40f3908 100644
--- a/core/fpdfdoc/doc_basic.cpp
+++ b/core/fpdfdoc/doc_basic.cpp
@@ -90,12 +90,13 @@ static CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode,
   if (pLimits) {
     CFX_ByteString csLeft = pLimits->GetStringAt(0);
     CFX_ByteString csRight = pLimits->GetStringAt(1);
-    if (csLeft.Compare(csRight) > 0) {
+    if (csLeft.Compare(csRight.AsByteStringC()) > 0) {
       CFX_ByteString csTmp = csRight;
       csRight = csLeft;
       csLeft = csTmp;
     }
-    if (csName.Compare(csLeft) < 0 || csName.Compare(csRight) > 0) {
+    if (csName.Compare(csLeft.AsByteStringC()) < 0 ||
+        csName.Compare(csRight.AsByteStringC()) > 0) {
       return NULL;
     }
   }
@@ -104,7 +105,7 @@ static CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode,
     uint32_t dwCount = pNames->GetCount() / 2;
     for (uint32_t i = 0; i < dwCount; i++) {
       CFX_ByteString csValue = pNames->GetStringAt(i * 2);
-      int32_t iCompare = csValue.Compare(csName);
+      int32_t iCompare = csValue.Compare(csName.AsByteStringC());
       if (iCompare <= 0) {
         if (ppFind) {
           *ppFind = pNames;
@@ -500,7 +501,7 @@ int32_t CPDF_PageLabel::GetPageByLabel(const CFX_ByteStringC& bsLabel) const {
   CFX_ByteString bsOrig = bsLabel;
   for (int i = 0; i < nPages; i++) {
     bsLbl = PDF_EncodeText(GetLabel(i));
-    if (!bsLbl.Compare(bsOrig)) {
+    if (!bsLbl.Compare(bsOrig.AsByteStringC())) {
       return i;
     }
   }
@@ -512,6 +513,5 @@ int32_t CPDF_PageLabel::GetPageByLabel(const CFX_ByteStringC& bsLabel) const {
   return -1;
 }
 int32_t CPDF_PageLabel::GetPageByLabel(const CFX_WideStringC& wsLabel) const {
-  CFX_ByteString bsLabel = PDF_EncodeText(wsLabel.GetPtr());
-  return GetPageByLabel(bsLabel);
+  return GetPageByLabel(PDF_EncodeText(wsLabel.GetPtr()).AsByteStringC());
 }