Remove FXDIB_BLEND_UNSUPPORTED.

The blend mode is never set to this value.

Change-Id: I96cbadb055137a9de45f0082c81a7b8aedb9a427
Reviewed-on: https://pdfium-review.googlesource.com/c/44544
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
index 4ae5631..b29d5b3 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
@@ -439,8 +439,7 @@
   graphD.strokeAlpha = pPageObj->m_GeneralState.GetStrokeAlpha();
   graphD.blendType = pPageObj->m_GeneralState.GetBlendType();
   if (graphD.fillAlpha == 1.0f && graphD.strokeAlpha == 1.0f &&
-      (graphD.blendType == FXDIB_BLEND_UNSUPPORTED ||
-       graphD.blendType == FXDIB_BLEND_NORMAL)) {
+      graphD.blendType == FXDIB_BLEND_NORMAL) {
     return;
   }
 
@@ -456,8 +455,7 @@
     if (graphD.strokeAlpha != 1.0f)
       gsDict->SetNewFor<CPDF_Number>("CA", graphD.strokeAlpha);
 
-    if (graphD.blendType != FXDIB_BLEND_UNSUPPORTED &&
-        graphD.blendType != FXDIB_BLEND_NORMAL) {
+    if (graphD.blendType != FXDIB_BLEND_NORMAL) {
       gsDict->SetNewFor<CPDF_Name>("BM",
                                    pPageObj->m_GeneralState.GetBlendMode());
     }
diff --git a/core/fpdfapi/render/cpdf_renderstatus.cpp b/core/fpdfapi/render/cpdf_renderstatus.cpp
index 26ce0a6..4e9c69b 100644
--- a/core/fpdfapi/render/cpdf_renderstatus.cpp
+++ b/core/fpdfapi/render/cpdf_renderstatus.cpp
@@ -1438,9 +1438,6 @@
   DebugVerifyDeviceIsPreMultiplied();
 #endif
   int blend_type = pPageObj->m_GeneralState.GetBlendType();
-  if (blend_type == FXDIB_BLEND_UNSUPPORTED)
-    return true;
-
   CPDF_Dictionary* pSMaskDict =
       ToDictionary(pPageObj->m_GeneralState.GetSoftMask());
   if (pSMaskDict) {
diff --git a/core/fxge/fx_dib.h b/core/fxge/fx_dib.h
index 7d8ca5f..0779de3 100644
--- a/core/fxge/fx_dib.h
+++ b/core/fxge/fx_dib.h
@@ -72,7 +72,6 @@
 #define FXDIB_BLEND_SATURATION 22
 #define FXDIB_BLEND_COLOR 23
 #define FXDIB_BLEND_LUMINOSITY 24
-#define FXDIB_BLEND_UNSUPPORTED -1
 
 constexpr uint32_t FXSYS_BGR(uint8_t b, uint8_t g, uint8_t r) {
   return (b << 16) | (g << 8) | r;