Avoid string allocs for CMap_GetString() return value.

StringC's are all that's needed here. Also CMap_GetString()
and GetCode() are side-effect free, so remove calls where
the value is not used.

Review URL: https://codereview.chromium.org/1889003002

3 files changed, 6 insertions, 7 deletions

diff --git a/core/fpdfapi/fpdf_font/cpdf_cidfont.cpp b/core/fpdfapi/fpdf_font/cpdf_cidfont.cpp
index 034f6f6ece..6089e75ec2 100644
--- a/core/fpdfapi/fpdf_font/cpdf_cidfont.cpp
+++ b/core/fpdfapi/fpdf_font/cpdf_cidfont.cpp
@@ -401,7 +401,8 @@ FX_BOOL CPDF_CIDFont::Load() {
   if (m_Charset == CIDSET_UNKNOWN) {
     CPDF_Dictionary* pCIDInfo = pCIDFontDict->GetDictBy("CIDSystemInfo");
     if (pCIDInfo) {
-      m_Charset = CharsetFromOrdering(pCIDInfo->GetStringBy("Ordering"));
+      m_Charset =
+          CharsetFromOrdering(pCIDInfo->GetStringBy("Ordering").AsStringC());
     }
   }
   if (m_Charset != CIDSET_UNKNOWN)
diff --git a/core/fpdfapi/fpdf_font/font_int.h b/core/fpdfapi/fpdf_font/font_int.h
index fc69b0cbd9..792377ebf0 100644
--- a/core/fpdfapi/fpdf_font/font_int.h
+++ b/core/fpdfapi/fpdf_font/font_int.h
@@ -22,7 +22,7 @@ typedef void* FXFT_Library;
 
 short TT2PDF(int m, FXFT_Face face);
 FX_BOOL FT_UseTTCharmap(FXFT_Face face, int platform_id, int encoding_id);
-CIDSet CharsetFromOrdering(const CFX_ByteString& ordering);
+CIDSet CharsetFromOrdering(const CFX_ByteStringC& ordering);
 
 class CPDF_CMapManager {
  public:
diff --git a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
index f84fa9f2f9..d5fe4dfd92 100644
--- a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
+++ b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
@@ -190,7 +190,7 @@ CIDSet CIDSetFromSizeT(size_t index) {
   return static_cast<CIDSet>(index);
 }
 
-CFX_ByteString CMap_GetString(const CFX_ByteStringC& word) {
+CFX_ByteStringC CMap_GetString(const CFX_ByteStringC& word) {
   return word.Mid(1, word.GetLength() - 2);
 }
 
@@ -407,13 +407,11 @@ void CPDF_CMapParser::ParseWord(const CFX_ByteStringC& word) {
     }
     m_CodeSeq = 0;
   } else if (m_Status == 3) {
-    CMap_GetString(word);
     m_Status = 0;
   } else if (m_Status == 4) {
     m_pCMap->m_Charset = CharsetFromOrdering(CMap_GetString(word));
     m_Status = 0;
   } else if (m_Status == 5) {
-    CMap_GetCode(word);
     m_Status = 0;
   } else if (m_Status == 6) {
     m_pCMap->m_bVertical = CMap_GetCode(word);
@@ -788,9 +786,9 @@ void CPDF_CID2UnicodeMap::Load(CPDF_CMapManager* pMgr,
   FPDFAPI_LoadCID2UnicodeMap(charset, m_pEmbeddedMap, m_EmbeddedCount);
 }
 
-CIDSet CharsetFromOrdering(const CFX_ByteString& ordering) {
+CIDSet CharsetFromOrdering(const CFX_ByteStringC& ordering) {
   for (size_t charset = 1; charset < FX_ArraySize(g_CharsetNames); ++charset) {
-    if (ordering == CFX_ByteStringC(g_CharsetNames[charset]))
+    if (ordering == g_CharsetNames[charset])
       return CIDSetFromSizeT(charset);
   }
   return CIDSET_UNKNOWN;