Fix a bunch of sign mismatch warnings.

core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp

Index: core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp
diff --git a/core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp b/core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp
index ad33a3f0a6e80a8ce2f870cb2ad94e36f5b17f25..331de18c100bc934685bdcb14d55f22f9c7188ba 100644
--- a/core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp
+++ b/core/src/fpdfapi/fpdf_font/fpdf_font_cid.cpp
@@ -21,7 +21,7 @@ CPDF_CMapManager::~CPDF_CMapManager() {
     delete pair.second;
   }
   m_CMaps.clear();
-  for (int i = 0; i < FX_ArraySize(m_CID2UnicodeMaps); ++i) {
+  for (size_t i = 0; i < FX_ArraySize(m_CID2UnicodeMaps); ++i) {
     delete m_CID2UnicodeMaps[i];
   }
 }
@@ -63,20 +63,19 @@ void CPDF_CMapManager::ReloadAll() {
     CPDF_CMap* pCMap = pair.second;
     pCMap->LoadPredefined(this, pair.first, FALSE);
   }
-  for (int i = 0; i < FX_ArraySize(m_CID2UnicodeMaps); ++i) {
+  for (size_t i = 0; i < FX_ArraySize(m_CID2UnicodeMaps); ++i) {
     if (CPDF_CID2UnicodeMap* pMap = m_CID2UnicodeMaps[i]) {
       pMap->Load(this, i, FALSE);
     }
   }
 }
-CPDF_CID2UnicodeMap* CPDF_CMapManager::GetCID2UnicodeMap(int charset,
+CPDF_CID2UnicodeMap* CPDF_CMapManager::GetCID2UnicodeMap(size_t charset,
                                                          FX_BOOL bPromptCJK) {
-  if (m_CID2UnicodeMaps[charset] == NULL) {
+  if (!m_CID2UnicodeMaps[charset])
     m_CID2UnicodeMaps[charset] = LoadCID2UnicodeMap(charset, bPromptCJK);
-  }
   return m_CID2UnicodeMaps[charset];
 }
-CPDF_CID2UnicodeMap* CPDF_CMapManager::LoadCID2UnicodeMap(int charset,
+CPDF_CID2UnicodeMap* CPDF_CMapManager::LoadCID2UnicodeMap(size_t charset,
                                                           FX_BOOL bPromptCJK) {
   CPDF_CID2UnicodeMap* pMap = new CPDF_CID2UnicodeMap();
   if (!pMap->Initialize()) {
@@ -769,11 +768,11 @@ FX_WCHAR CPDF_CID2UnicodeMap::UnicodeFromCID(FX_WORD CID) {
   }
   return 0;
 }
-void FPDFAPI_LoadCID2UnicodeMap(int charset,
+void FPDFAPI_LoadCID2UnicodeMap(size_t charset,
                                 const FX_WORD*& pMap,
                                 FX_DWORD& count);
 void CPDF_CID2UnicodeMap::Load(CPDF_CMapManager* pMgr,
-                               int charset,
+                               size_t charset,
                                FX_BOOL bPromptCJK) {
   m_Charset = charset;
   FPDFAPI_LoadCID2UnicodeMap(charset, m_pEmbeddedMap, m_EmbeddedCount);