Replace an enum in CPDF_SeparationCS with a bool.

One of the three enum values is unused. That leaves two, so the member
variable can just become of type bool, which is still easy to understand
in this case.

Change-Id: I59fae01b7151d1008b15c6eb54ea6ed74649fa5d
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/81774
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index a9edf79..af6d8e6 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -293,10 +293,9 @@
                   std::set<const CPDF_Object*>* pVisited) override;
 
  private:
-  enum { None, All, Colorant } m_Type;
-
   explicit CPDF_SeparationCS(CPDF_Document* pDoc);
 
+  bool m_IsNoneType;
   RetainPtr<CPDF_ColorSpace> m_pAltCS;
   std::unique_ptr<const CPDF_Function> m_pFunc;
 };
@@ -1238,13 +1237,10 @@
 uint32_t CPDF_SeparationCS::v_Load(CPDF_Document* pDoc,
                                    const CPDF_Array* pArray,
                                    std::set<const CPDF_Object*>* pVisited) {
-  ByteString name = pArray->GetStringAt(1);
-  if (name == "None") {
-    m_Type = None;
+  m_IsNoneType = pArray->GetStringAt(1) == "None";
+  if (m_IsNoneType)
     return 1;
-  }
 
-  m_Type = Colorant;
   const CPDF_Object* pAltCS = pArray->GetDirectObjectAt(2);
   if (pAltCS == m_pArray)
     return 0;
@@ -1269,7 +1265,7 @@
                                float* R,
                                float* G,
                                float* B) const {
-  if (m_Type == None)
+  if (m_IsNoneType)
     return false;
 
   if (!m_pFunc) {