Add host resolver rules experimental flag for Cronet

components/cronet/url_request_context_config_unittest.cc

Index: components/cronet/url_request_context_config_unittest.cc
diff --git a/components/cronet/url_request_context_config_unittest.cc b/components/cronet/url_request_context_config_unittest.cc
index a0cef2abd3d616e890b8e029db4205f8f90d0382..fc7a25049f02970269ccc33df1d73b6e8b30c39f 100644
--- a/components/cronet/url_request_context_config_unittest.cc
+++ b/components/cronet/url_request_context_config_unittest.cc
@@ -16,7 +16,7 @@
 
 namespace cronet {
 
-TEST(URLRequestContextConfigTest, SetQuicExperimentalOptions) {
+TEST(URLRequestContextConfigTest, TestExperimentalOptionPassing) {
   URLRequestContextConfig config(
       // Enable QUIC.
       true,
@@ -47,7 +47,9 @@ TEST(URLRequestContextConfigTest, SetQuicExperimentalOptions) {
       "\"idle_connection_timeout_seconds\":300,"
       "\"close_sessions_on_ip_change\":true,"
       "\"connection_options\":\"TIME,TBBR,REJ\"},"
-      "\"AsyncDNS\":{\"enable\":true}}",
+      "\"AsyncDNS\":{\"enable\":true},"
+      "\"HostResolverRules\":{\"host_resolver_rules\":"
+      "\"MAP * 127.0.0.1\"}}",
       // Data reduction proxy key.
       "",
       // Data reduction proxy.
@@ -105,6 +107,11 @@ TEST(URLRequestContextConfigTest, SetQuicExperimentalOptions) {
 
   // Check AsyncDNS resolver is enabled.
   EXPECT_TRUE(context->host_resolver()->GetDnsConfigAsValue());
+
+  net::HostResolver::RequestInfo info(net::HostPortPair("abcde", 80));
+  net::AddressList addresses;
+  EXPECT_EQ(net::OK, context->host_resolver()->ResolveFromCache(
+                         info, &addresses, net::BoundNetLog()));
 }
 
 TEST(URLRequestContextConfigTest, SetQuicConnectionMigrationOptions) {