Add type cast definitions for CPDF_Name.

core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp

Index: core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 210d5433be7957a221e9d856a07213690a7bc928..9a1d48a41610b9f04f3f8ff5f68102cbb4aea555 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -308,27 +308,27 @@ void CPDF_DocPageData::ReleaseFont(CPDF_Dictionary* pFontDict) {
 
 CPDF_ColorSpace* CPDF_DocPageData::GetColorSpace(CPDF_Object* pCSObj,
                                                  CPDF_Dictionary* pResources) {
-  if (!pCSObj) {
-    return NULL;
-  }
-  if (pCSObj->GetType() == PDFOBJ_NAME) {
+  if (!pCSObj)
+    return nullptr;
+
+  if (pCSObj->IsName()) {
     CFX_ByteString name = pCSObj->GetConstString();
     CPDF_ColorSpace* pCS = _CSFromName(name);
     if (!pCS && pResources) {
       CPDF_Dictionary* pList = pResources->GetDict(FX_BSTRC("ColorSpace"));
       if (pList) {
         pCSObj = pList->GetElementValue(name);
-        return GetColorSpace(pCSObj, NULL);
+        return GetColorSpace(pCSObj, nullptr);
       }
     }
-    if (pCS == NULL || pResources == NULL) {
+    if (!pCS || !pResources)
       return pCS;
-    }
+
     CPDF_Dictionary* pColorSpaces = pResources->GetDict(FX_BSTRC("ColorSpace"));
-    if (pColorSpaces == NULL) {
+    if (!pColorSpaces)
       return pCS;
-    }
-    CPDF_Object* pDefaultCS = NULL;
+
+    CPDF_Object* pDefaultCS = nullptr;
     switch (pCS->GetFamily()) {
       case PDFCS_DEVICERGB:
         pDefaultCS = pColorSpaces->GetElementValue(FX_BSTRC("DefaultRGB"));
@@ -340,10 +340,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpace(CPDF_Object* pCSObj,
         pDefaultCS = pColorSpaces->GetElementValue(FX_BSTRC("DefaultCMYK"));
         break;
     }
-    if (pDefaultCS == NULL) {
-      return pCS;
-    }
-    return GetColorSpace(pDefaultCS, NULL);
+    return pDefaultCS ? GetColorSpace(pDefaultCS, nullptr) : pCS;
   }
 
   if (pCSObj->GetType() != PDFOBJ_ARRAY)