diff --git a/core/fpdfapi/cmaps/CNS1/cmaps_cns1.cpp b/core/fpdfapi/cmaps/CNS1/cmaps_cns1.cpp
index 80c31d6..810104e 100644
--- a/core/fpdfapi/cmaps/CNS1/cmaps_cns1.cpp
+++ b/core/fpdfapi/cmaps/CNS1/cmaps_cns1.cpp
@@ -6,6 +6,8 @@
 
 #include "core/fpdfapi/cmaps/CNS1/cmaps_cns1.h"
 
+#include "core/fxcrt/fx_memory.h"
+
 const FXCMAP_CMap g_FXCMAP_CNS1_cmaps[] = {
     {"B5pc-H", g_FXCMAP_B5pc_H_0, nullptr, 247, 0, FXCMAP_CMap::Range, 0},
     {"B5pc-V", g_FXCMAP_B5pc_V_0, nullptr, 12, 0, FXCMAP_CMap::Range, -1},
diff --git a/core/fpdfapi/cmaps/GB1/cmaps_gb1.cpp b/core/fpdfapi/cmaps/GB1/cmaps_gb1.cpp
index 0ba0db7..a598091 100644
--- a/core/fpdfapi/cmaps/GB1/cmaps_gb1.cpp
+++ b/core/fpdfapi/cmaps/GB1/cmaps_gb1.cpp
@@ -6,6 +6,8 @@
 
 #include "core/fpdfapi/cmaps/GB1/cmaps_gb1.h"
 
+#include "core/fxcrt/fx_memory.h"
+
 const FXCMAP_CMap g_FXCMAP_GB1_cmaps[] = {
     {"GB-EUC-H", g_FXCMAP_GB_EUC_H_0, nullptr, 90, 0, FXCMAP_CMap::Range, 0},
     {"GB-EUC-V", g_FXCMAP_GB_EUC_V_0, nullptr, 20, 0, FXCMAP_CMap::Range, -1},
diff --git a/core/fpdfapi/cmaps/Japan1/cmaps_japan1.cpp b/core/fpdfapi/cmaps/Japan1/cmaps_japan1.cpp
index 9b9cfc3..5a48c77 100644
--- a/core/fpdfapi/cmaps/Japan1/cmaps_japan1.cpp
+++ b/core/fpdfapi/cmaps/Japan1/cmaps_japan1.cpp
@@ -6,6 +6,8 @@
 
 #include "core/fpdfapi/cmaps/Japan1/cmaps_japan1.h"
 
+#include "core/fxcrt/fx_memory.h"
+
 const FXCMAP_CMap g_FXCMAP_Japan1_cmaps[] = {
     {"83pv-RKSJ-H", g_FXCMAP_83pv_RKSJ_H_1, nullptr, 222, 0, FXCMAP_CMap::Range,
      0},
diff --git a/core/fpdfapi/cmaps/Korea1/cmaps_korea1.cpp b/core/fpdfapi/cmaps/Korea1/cmaps_korea1.cpp
index a95ab3e..7362ff8 100644
--- a/core/fpdfapi/cmaps/Korea1/cmaps_korea1.cpp
+++ b/core/fpdfapi/cmaps/Korea1/cmaps_korea1.cpp
@@ -6,6 +6,8 @@
 
 #include "core/fpdfapi/cmaps/Korea1/cmaps_korea1.h"
 
+#include "core/fxcrt/fx_memory.h"
+
 const FXCMAP_CMap g_FXCMAP_Korea1_cmaps[] = {
     {"KSC-EUC-H", g_FXCMAP_KSC_EUC_H_0, nullptr, 467, 0, FXCMAP_CMap::Range, 0},
     {"KSC-EUC-V", g_FXCMAP_KSC_EUC_V_0, nullptr, 16, 0, FXCMAP_CMap::Range, -1},
diff --git a/core/fpdfapi/cmaps/fpdf_cmaps.cpp b/core/fpdfapi/cmaps/fpdf_cmaps.cpp
index 750c04d..5c89faf 100644
--- a/core/fpdfapi/cmaps/fpdf_cmaps.cpp
+++ b/core/fpdfapi/cmaps/fpdf_cmaps.cpp
@@ -8,8 +8,6 @@
 
 #include <algorithm>
 
-#include "third_party/base/span.h"
-
 namespace {
 
 struct SingleCmap {
@@ -30,7 +28,7 @@
 }  // namespace
 
 const FXCMAP_CMap* FindEmbeddedCMap(pdfium::span<const FXCMAP_CMap> pCMaps,
-                                    const ByteString& bsName) {
+                                    ByteStringView bsName) {
   for (size_t i = 0; i < pCMaps.size(); i++) {
     if (bsName == pCMaps[i].m_Name)
       return &pCMaps[i];
diff --git a/core/fpdfapi/cmaps/fpdf_cmaps.h b/core/fpdfapi/cmaps/fpdf_cmaps.h
index c84dc57..2c7548a 100644
--- a/core/fpdfapi/cmaps/fpdf_cmaps.h
+++ b/core/fpdfapi/cmaps/fpdf_cmaps.h
@@ -7,8 +7,9 @@
 #ifndef CORE_FPDFAPI_CMAPS_FPDF_CMAPS_H_
 #define CORE_FPDFAPI_CMAPS_FPDF_CMAPS_H_
 
+#include <stdint.h>
+
 #include "core/fxcrt/fx_string.h"
-#include "core/fxcrt/fx_system.h"
 #include "third_party/base/span.h"
 
 struct FXCMAP_DWordCIDMap {
@@ -31,7 +32,7 @@
 };
 
 const FXCMAP_CMap* FindEmbeddedCMap(pdfium::span<const FXCMAP_CMap> pCMaps,
-                                    const ByteString& name);
+                                    ByteStringView name);
 uint16_t CIDFromCharCode(const FXCMAP_CMap* pMap, uint32_t charcode);
 uint32_t CharCodeFromCID(const FXCMAP_CMap* pMap, uint16_t cid);
 
diff --git a/core/fpdfapi/font/cpdf_cidfont.cpp b/core/fpdfapi/font/cpdf_cidfont.cpp
index 19dbf86..0c02b9e 100644
--- a/core/fpdfapi/font/cpdf_cidfont.cpp
+++ b/core/fpdfapi/font/cpdf_cidfont.cpp
@@ -360,7 +360,8 @@
   } else if (CPDF_Stream* pStream = pEncoding->AsStream()) {
     auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pStream);
     pAcc->LoadAllDataFiltered();
-    m_pCMap = pdfium::MakeRetain<CPDF_CMap>(pAcc->GetSpan());
+    pdfium::span<const uint8_t> span = pAcc->GetSpan();
+    m_pCMap = pdfium::MakeRetain<CPDF_CMap>(span);
   } else {
     return false;
   }
diff --git a/core/fpdfapi/font/cpdf_cmap.cpp b/core/fpdfapi/font/cpdf_cmap.cpp
index 9d1603b..844bc5f 100644
--- a/core/fpdfapi/font/cpdf_cmap.cpp
+++ b/core/fpdfapi/font/cpdf_cmap.cpp
@@ -181,12 +181,11 @@
     {"UniKS-UTF16", CIDSET_KOREA1, CIDCODING_UTF16, CPDF_CMap::TwoBytes, 0, {}},
 };
 
-const PredefinedCMap* GetPredefinedCMap(const ByteString& bsPredefinedName) {
-  ByteString cmapid = bsPredefinedName;
+const PredefinedCMap* GetPredefinedCMap(ByteStringView cmapid) {
   if (cmapid.GetLength() > 2)
     cmapid = cmapid.First(cmapid.GetLength() - 2);
   for (const auto& map : kPredefinedCMaps) {
-    if (cmapid == ByteStringView(map.m_pName))
+    if (cmapid == map.m_pName)
       return &map;
   }
   return nullptr;
@@ -258,7 +257,7 @@
 
 }  // namespace
 
-CPDF_CMap::CPDF_CMap(const ByteString& bsPredefinedName)
+CPDF_CMap::CPDF_CMap(ByteStringView bsPredefinedName)
     : m_bVertical(bsPredefinedName.Back() == 'V') {
   if (bsPredefinedName == "Identity-H" || bsPredefinedName == "Identity-V") {
     m_Coding = CIDCODING_CID;
diff --git a/core/fpdfapi/font/cpdf_cmap.h b/core/fpdfapi/font/cpdf_cmap.h
index 6754c71..e2caf8d 100644
--- a/core/fpdfapi/font/cpdf_cmap.h
+++ b/core/fpdfapi/font/cpdf_cmap.h
@@ -78,7 +78,7 @@
   }
 
  private:
-  explicit CPDF_CMap(const ByteString& bsPredefinedName);
+  explicit CPDF_CMap(ByteStringView bsPredefinedName);
   explicit CPDF_CMap(pdfium::span<const uint8_t> spEmbeddedData);
   ~CPDF_CMap() override;
 
diff --git a/core/fpdfapi/font/cpdf_cmapmanager.cpp b/core/fpdfapi/font/cpdf_cmapmanager.cpp
index 4129716..726b648 100644
--- a/core/fpdfapi/font/cpdf_cmapmanager.cpp
+++ b/core/fpdfapi/font/cpdf_cmapmanager.cpp
@@ -14,7 +14,7 @@
 
 namespace {
 
-RetainPtr<const CPDF_CMap> LoadPredefinedCMap(ByteString name) {
+RetainPtr<const CPDF_CMap> LoadPredefinedCMap(ByteStringView name) {
   if (!name.IsEmpty() && name[0] == '/')
     name = name.Last(name.GetLength() - 1);
   return pdfium::MakeRetain<CPDF_CMap>(name);
@@ -32,7 +32,7 @@
   if (it != m_CMaps.end())
     return it->second;
 
-  RetainPtr<const CPDF_CMap> pCMap = LoadPredefinedCMap(name);
+  RetainPtr<const CPDF_CMap> pCMap = LoadPredefinedCMap(name.AsStringView());
   if (!name.IsEmpty())
     m_CMaps[name] = pCMap;