Remove `FXDIB_Format::k8bppRgba`.

Another format that is never used.

Change-Id: I35a01514ae481f3e294bde7eb80b7eadecab4447
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/75532
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxge/dib/cfx_dibbase.cpp b/core/fxge/dib/cfx_dibbase.cpp
index c24ac1f..e8662f2 100644
--- a/core/fxge/dib/cfx_dibbase.cpp
+++ b/core/fxge/dib/cfx_dibbase.cpp
@@ -1148,8 +1148,7 @@
       return ConvertBuffer_8bppMask(bpp, dest_buf, dest_pitch, width, height,
                                     pSrcBitmap, src_left, src_top);
     }
-    case FXDIB_Format::k8bppRgb:
-    case FXDIB_Format::k8bppRgba: {
+    case FXDIB_Format::k8bppRgb: {
       const bool bpp_1_or_8 = (bpp == 1 || bpp == 8);
       if (bpp_1_or_8 && !pSrcBitmap->HasPalette()) {
         return ConvertBuffer(FXDIB_Format::k8bppMask, dest_buf, dest_pitch,
diff --git a/core/fxge/dib/fx_dib.h b/core/fxge/dib/fx_dib.h
index 437fa70..bc87785 100644
--- a/core/fxge/dib/fx_dib.h
+++ b/core/fxge/dib/fx_dib.h
@@ -21,7 +21,6 @@
   kRgb32 = 0x020,
   k1bppMask = 0x101,
   k8bppMask = 0x108,
-  k8bppRgba = 0x208,
   kRgba = 0x218,
   kArgb = 0x220,
 };
diff --git a/testing/fuzzers/pdf_scanlinecompositor_fuzzer.cc b/testing/fuzzers/pdf_scanlinecompositor_fuzzer.cc
index 0e35fcd..6ffcf65 100644
--- a/testing/fuzzers/pdf_scanlinecompositor_fuzzer.cc
+++ b/testing/fuzzers/pdf_scanlinecompositor_fuzzer.cc
@@ -23,7 +23,7 @@
     FXDIB_Format::kRgb32,
     FXDIB_Format::k1bppMask,
     FXDIB_Format::k8bppMask,
-    FXDIB_Format::k8bppRgba,
+    FXDIB_Format::kInvalid /* Was FXDIB_Format::k8bppRgba */,
     FXDIB_Format::kRgba,
     FXDIB_Format::kArgb,
     FXDIB_Format::kInvalid /* Was FXDIB_Format::k1bppCmyk */,