[libfuzzer] tweaking mp4 fuzzer: dictionary and max_len.

testing/libfuzzer/fuzzers/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Individual libfuzzer tests that didn't find their home yet.
 
 import("//build/config/features.gni")
 import("//media/media_options.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//third_party/pdfium/pdfium.gni")
@@ skipping 41 matching lines @@
 
 if (proprietary_codecs) {
   fuzzer_test("mp4_box_reader_fuzzer") {
     sources = [
       "mp4_box_reader_fuzzer.cc",
     ]
     deps = [
       "//base",
       "//media",
     ]
+    libfuzzer_options = "mp4_box_reader_fuzzer.options"
+    dict = "dicts/mp4.dict"
   }
 }
 
 if (enable_mse_mpeg2ts_stream_parser) {
   fuzzer_test("es_parser_adts_fuzzer") {
     sources = [
       "es_parser_adts_fuzzer.cc",
     ]
     deps = [
       "//base",
@@ skipping 234 matching lines @@
 fuzzer_test("libxml_xml_regexp_compile_fuzzer") {
   sources = [
     "libxml_xml_regexp_compile_fuzzer.cc",
   ]
   deps = [
     "//third_party/libxml",
   ]
   libfuzzer_options = "libxml_xml_regexp_compile_fuzzer.options"
   additional_configs = [ "//testing/libfuzzer:no_clusterfuzz" ]
 }