Add a fuzzer for DNS hosts parser

net/dns/dns_hosts_parse_fuzzer.cc

Index: net/dns/dns_hosts_parse_fuzzer.cc
diff --git a/components/webcrypto/rsa_import_key_pkcs8_fuzzer.cc b/net/dns/dns_hosts_parse_fuzzer.cc
similarity index 64%
copy from components/webcrypto/rsa_import_key_pkcs8_fuzzer.cc
copy to net/dns/dns_hosts_parse_fuzzer.cc
index 184012299e576afa4f344f2a04c7762e27a78ca3..0f82e8ab51051de82a7a9fd6c3c55c57cd50536a 100644
--- a/components/webcrypto/rsa_import_key_pkcs8_fuzzer.cc
+++ b/net/dns/dns_hosts_parse_fuzzer.cc
@@ -5,11 +5,14 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "components/webcrypto/fuzzer_support.h"
+#include <string>
+
+#include "net/dns/dns_hosts.h"
 
 // Entry point for LibFuzzer.
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  webcrypto::ImportRsaKeyFromDerFuzzData(data, size,
-                                         blink::WebCryptoKeyFormatPkcs8);
+  std::string input(reinterpret_cast<const char*>(data), size);
+  net::DnsHosts dns_hosts;
+  net::ParseHosts(input, &dns_hosts);

[mmenke, 2016/04/28 16:20:03]

I'd suggest calling ParseHostsWithCommaModeForTesting with both comma modes on
the input, instead of ParseHosts, just to make sure we cover all our bases.

[Zhongyi Shi, 2016/04/28 17:35:17]

Done. Thanks:D

   return 0;
 }