Merge "Reduce test time of ResolverTest#GetAddrInfoV6_nonresponsive" am: 0c1505dbb3

    constexpr char listen_srv[] = "53";

    constexpr char host_name1[] = "ohayou.example.com.";

    constexpr char host_name2[] = "ciao.example.com.";

    const std::vector<std::string> defaultSearchDomain = {"example.com"};

    // The minimal timeout is 1000ms, so we can't decrease timeout

    // So reduce retry count.

    const std::vector<int> reduceRetryParams = {

            300,      // sample validity in seconds

            25,       // success threshod in percent

            8,    8,  // {MIN,MAX}_SAMPLES

            1000,     // BASE_TIMEOUT_MSEC

            1,        // retry count

    };

    const std::vector<DnsRecord> records0 = {

            {host_name1, ns_type::ns_t_aaaa, "2001:db8::5"},

            {host_name2, ns_type::ns_t_aaaa, "2001:db8::5"},

    dns0.setResponseProbability(0.0);

    StartDns(dns0, records0);

    StartDns(dns1, records1);

    ASSERT_TRUE(mDnsClient.SetResolversForNetwork({listen_addr0, listen_addr1}));

    ASSERT_TRUE(mDnsClient.SetResolversForNetwork({listen_addr0, listen_addr1}, defaultSearchDomain,

                                                  reduceRetryParams));

    const addrinfo hints = {.ai_family = AF_INET6};

    // Specify ai_socktype to make getaddrinfo will only query 1 time

    const addrinfo hints = {.ai_family = AF_INET6, .ai_socktype = SOCK_STREAM};

    // dns0 will ignore the request, and we'll fallback to dns1 after the first

    // retry.

    EXPECT_EQ(1U, GetNumQueries(dns1, host_name1));

    // Now make dns1 also ignore 100% requests... The resolve should alternate

    // retries between the nameservers and fail after 4 attempts.

    // queries between the nameservers and fail

    dns1.setResponseProbability(0.0);

    addrinfo* result2 = nullptr;

    EXPECT_EQ(EAI_NODATA, getaddrinfo(host_name2, nullptr, &hints, &result2));

    EXPECT_EQ(nullptr, result2);

    EXPECT_EQ(4U, GetNumQueries(dns0, host_name2));

    EXPECT_EQ(4U, GetNumQueries(dns1, host_name2));

    EXPECT_EQ(1U, GetNumQueries(dns0, host_name2));

    EXPECT_EQ(1U, GetNumQueries(dns1, host_name2));

}

TEST_F(ResolverTest, GetAddrInfoV6_concurrent) {