Fuzz LookupStringInFixedSet

Adds a dedicated fuzzer for LookupStringInFixedSet() as the function is
no longer tested by the GetDomainAndRegistry fuzzer.

The fuzzer is using a forward generated DAFSA based on the public suffix
list and reuses the dictionary from the GetDomainAndRegistry fuzzer.

BUG=1048702

Change-Id: If123985c60efab57faddaa934e6674042dd4d07a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2050498Reviewed-by: Ryan Sleevi <rsleevi@chromium.org>
Commit-Queue: Olle Liljenzin <ollel@opera.com>
Cr-Commit-Position: refs/heads/master@{#740799}

net/BUILD.gn

@@ -5009,6 +5009,17 @@ fuzzer_test("net_get_domain_and_registry_fuzzer") {
   dict = "data/fuzzer_dictionaries/net_get_domain_and_registry_fuzzer.dict"
 }
 
+fuzzer_test("net_lookup_string_in_fixed_set_fuzzer") {
+  sources = [ "base/lookup_string_in_fixed_set_fuzzer.cc" ]
+  deps = [
+    ":net_fuzzer_test_support",
+    "//base",
+    "//net",
+    "//net/base/registry_controlled_domains:lookup_strings_test_sets",
+  ]
+  dict = "data/fuzzer_dictionaries/net_get_domain_and_registry_fuzzer.dict"
+}
+
 fuzzer_test("net_cert_ct_decode_signed_certificate_timestamp_fuzzer") {
   sources = [ "cert/decode_signed_certificate_timestamp_fuzzer.cc" ]
   deps = [

net/base/lookup_string_in_fixed_set_fuzzer.cc

+// Copyright 2020 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.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "net/base/lookup_string_in_fixed_set.h"
+
+namespace {
+#include "net/base/registry_controlled_domains/effective_tld_names-inc.cc"
+}  // namespace
+
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  net::LookupStringInFixedSet(kDafsa, sizeof(kDafsa),
+                              reinterpret_cast<const char*>(data), size);
+  return 0;
+}

net/base/registry_controlled_domains/BUILD.gn

@@ -25,6 +25,7 @@ action_foreach("registry_controlled_domains") {
 action_foreach("lookup_strings_test_sets") {
   script = "//net/tools/dafsa/make_dafsa.py"
   sources = [
+    "effective_tld_names.gperf",
     "effective_tld_names_unittest1.gperf",
     "effective_tld_names_unittest2.gperf",
     "effective_tld_names_unittest3.gperf",