Make dns_fuzz_stub read and parse JSON test case

net/tools/dns_fuzz_stub/dns_fuzz_stub.cc

Index: net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
diff --git a/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc b/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
index 4dcae720f85de3e23f00feef4454e530a0a637db..85b4f8e6909c08ba6a3f88f6bfc915465cc45b3d 100644
--- a/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
+++ b/net/tools/dns_fuzz_stub/dns_fuzz_stub.cc
@@ -162,6 +162,11 @@ int main(int argc, char** argv) {
             << " qtype=" << qtype;
   LOG(INFO) << "Response: " << resp_buf.size() << " bytes";
 
+  if (strcmp("pleasecrash", qname_dotted.c_str()) == 0) {
+    int *p = NULL;
+    *p = 0;
+  }
+
   std::string qname;
   if (!net::DNSDomainFromDot(qname_dotted, &qname)) {
     LOG(ERROR) << "DNSDomainFromDot(" << qname_dotted << ") failed.";