Add fuzzer for cmap parsing

testing/libfuzzer/pdf_cmap_fuzzer.cc

Index: testing/libfuzzer/pdf_cmap_fuzzer.cc
diff --git a/testing/libfuzzer/pdf_codec_jpeg_fuzzer.cc b/testing/libfuzzer/pdf_cmap_fuzzer.cc
similarity index 65%
copy from testing/libfuzzer/pdf_codec_jpeg_fuzzer.cc
copy to testing/libfuzzer/pdf_cmap_fuzzer.cc
index 862bfad535ca432018e44346aa2486d770b27e3b..652e6b887f4d867ba4bf44c4f0801103ebf01097 100644
--- a/testing/libfuzzer/pdf_codec_jpeg_fuzzer.cc
+++ b/testing/libfuzzer/pdf_cmap_fuzzer.cc
@@ -2,8 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "testing/libfuzzer/xfa_codec_fuzzer.h"
+#include <cstdint>
+
+#include "core/fpdfapi/fpdf_font/font_int.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  return XFACodecFuzzer::Fuzz(data, size, FXCODEC_IMAGE_JPG);
+  CPDF_CMap cmap;
+  cmap.LoadEmbedded(data, size);
+  return 0;
 }