Add support for direct lookup resolver in NetworkServiceTest

While content::TestHostResolver simulates failure for non-local DNS
queries, some tests explicitly allow external DNS lookup using
net::RuleBasedHostResolverProc::AllowDirectLookup().

With kNetworkService feature enabled, appropriate host resolver rule
must be propagated to network process.

Change-Id: Icc6eb96a8ea346d408d04d23feb363789a1c5c97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1533954Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Commit-Queue: Tomasz Moniuszko <tmoniuszko@opera.com>
Cr-Commit-Position: refs/heads/master@{#644706}

content/public/test/browser_test_base.cc

@@ -536,13 +536,15 @@ void BrowserTestBase::InitializeNetworkProcess() {
          rule.resolver_type !=
              net::RuleBasedHostResolverProc::Rule::kResolverTypeIPLiteral) ||
         rule.address_family != net::AddressFamily::ADDRESS_FAMILY_UNSPECIFIED ||
-        !!rule.latency_ms || rule.replacement.empty())
+        !!rule.latency_ms)
       continue;
     network::mojom::RulePtr mojo_rule = network::mojom::Rule::New();
     if (rule.resolver_type ==
         net::RuleBasedHostResolverProc::Rule::kResolverTypeSystem) {
       mojo_rule->resolver_type =
-          network::mojom::ResolverType::kResolverTypeSystem;
+          rule.replacement.empty()
+              ? network::mojom::ResolverType::kResolverTypeDirectLookup
+              : network::mojom::ResolverType::kResolverTypeSystem;
     } else {
       mojo_rule->resolver_type =
           network::mojom::ResolverType::kResolverTypeIPLiteral;

content/public/test/network_service_test_helper.cc

@@ -90,18 +90,22 @@ class NetworkServiceTestHelper::NetworkServiceTestImpl
   // network::mojom::NetworkServiceTest:
   void AddRules(std::vector<network::mojom::RulePtr> rules,
                 AddRulesCallback callback) override {
+    auto* host_resolver = test_host_resolver_.host_resolver();
     for (const auto& rule : rules) {
-      if (rule->resolver_type ==
-          network::mojom::ResolverType::kResolverTypeFail) {
-        test_host_resolver_.host_resolver()->AddSimulatedFailure(
-            rule->host_pattern);
-      } else if (rule->resolver_type ==
-                 network::mojom::ResolverType::kResolverTypeIPLiteral) {
-        test_host_resolver_.host_resolver()->AddIPLiteralRule(
-            rule->host_pattern, rule->replacement, std::string());
-      } else {
-        test_host_resolver_.host_resolver()->AddRule(rule->host_pattern,
-                                                     rule->replacement);
+      switch (rule->resolver_type) {
+        case network::mojom::ResolverType::kResolverTypeFail:
+          host_resolver->AddSimulatedFailure(rule->host_pattern);
+          break;
+        case network::mojom::ResolverType::kResolverTypeIPLiteral:
+          host_resolver->AddIPLiteralRule(rule->host_pattern, rule->replacement,
+                                          std::string());
+          break;
+        case network::mojom::ResolverType::kResolverTypeDirectLookup:
+          host_resolver->AllowDirectLookup(rule->host_pattern);
+          break;
+        default:
+          host_resolver->AddRule(rule->host_pattern, rule->replacement);
+          break;
       }
     }
     std::move(callback).Run();

services/network/public/mojom/network_service_test.mojom

@@ -14,6 +14,7 @@ enum ResolverType {
   kResolverTypeFail,
   kResolverTypeSystem,
   kResolverTypeIPLiteral,
+  kResolverTypeDirectLookup,
 };
 
 struct Rule {