Use enum class for subtypes of CPDF_Annot.

fpdfsdk/fpdf_ext.cpp

Index: fpdfsdk/fpdf_ext.cpp
diff --git a/fpdfsdk/fpdf_ext.cpp b/fpdfsdk/fpdf_ext.cpp
index d03b4383ca3655daf66d26c784a441448fbd5e72..46bc7e57a48108c6e2636afb5b38dbbf7a083dee 100644
--- a/fpdfsdk/fpdf_ext.cpp
+++ b/fpdfsdk/fpdf_ext.cpp
@@ -46,33 +46,31 @@ FSDK_SetUnSpObjProcessHandler(UNSUPPORT_INFO* unsp_info) {
 }
 
 void CheckUnSupportAnnot(CPDF_Document* pDoc, const CPDF_Annot* pPDFAnnot) {
-  CFX_ByteString cbSubType = pPDFAnnot->GetSubtype();
-  if (cbSubType.Compare("3D") == 0) {
+  CPDF_Annot::Subtype nAnnotSubtype = pPDFAnnot->GetSubtype();
+  if (nAnnotSubtype == CPDF_Annot::Subtype::THREED) {
     FPDF_UnSupportError(FPDF_UNSP_ANNOT_3DANNOT);
-  } else if (cbSubType.Compare("Screen") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::SCREEN) {
     const CPDF_Dictionary* pAnnotDict = pPDFAnnot->GetAnnotDict();
     CFX_ByteString cbString;
     if (pAnnotDict->KeyExist("IT"))
       cbString = pAnnotDict->GetStringBy("IT");
     if (cbString.Compare("Img") != 0)
       FPDF_UnSupportError(FPDF_UNSP_ANNOT_SCREEN_MEDIA);
-  } else if (cbSubType.Compare("Movie") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::MOVIE) {
     FPDF_UnSupportError(FPDF_UNSP_ANNOT_MOVIE);
-  } else if (cbSubType.Compare("Sound") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::SOUND) {
     FPDF_UnSupportError(FPDF_UNSP_ANNOT_SOUND);
-  } else if (cbSubType.Compare("RichMedia") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::RICHMEDIA) {
     FPDF_UnSupportError(FPDF_UNSP_ANNOT_SCREEN_RICHMEDIA);
-  } else if (cbSubType.Compare("FileAttachment") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::FILEATTACHMENT) {
     FPDF_UnSupportError(FPDF_UNSP_ANNOT_ATTACHMENT);
-  } else if (cbSubType.Compare("Widget") == 0) {
+  } else if (nAnnotSubtype == CPDF_Annot::Subtype::WIDGET) {
     const CPDF_Dictionary* pAnnotDict = pPDFAnnot->GetAnnotDict();
     CFX_ByteString cbString;
-    if (pAnnotDict->KeyExist("FT")) {
+    if (pAnnotDict->KeyExist("FT"))
       cbString = pAnnotDict->GetStringBy("FT");
-    }
-    if (cbString.Compare("Sig") == 0) {
+    if (cbString.Compare("Sig") == 0)
       FPDF_UnSupportError(FPDF_UNSP_ANNOT_SIG);
-    }
   }
 }