Link fuzzer pdf_scanlinecompositor_fuzzer in chromium.

Change-Id: If554173ce7a75ecbcbb0464288875a3a5510e6bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1869941Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Hui Yingst <nigi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708757}

pdf/pdfium/fuzzers/BUILD.gn

@@ -27,6 +27,7 @@ group("pdf_fuzzers") {
     ":pdf_hint_table_fuzzer",
     ":pdf_jpx_fuzzer",
     ":pdf_psengine_fuzzer",
+    ":pdf_scanlinecompositor_fuzzer",
     ":pdf_streamparser_fuzzer",
     ":pdf_xml_fuzzer",
     ":pdfium_fuzzer",
@@ -152,6 +153,13 @@ fuzzer_test("pdf_psengine_fuzzer") {
   ]
 }
 
+fuzzer_test("pdf_scanlinecompositor_fuzzer") {
+  sources = []
+  deps = [
+    "//third_party/pdfium/testing/fuzzers:pdf_scanlinecompositor_fuzzer_src",
+  ]
+}
+
 fuzzer_test("pdf_streamparser_fuzzer") {
   sources = []
   deps = [