Add disable_secure_dns field to URLRequest.

This change will allow URLRequests to bypass DoH during hostname
resolution.

Change-Id: Ic5a5346d57bf8fc639a82ff8b284f4e11893745d
Bug: 1012268
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1842562
Commit-Queue: Katharine Daly <dalyk@google.com>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Reviewed-by: Eric Orth <ericorth@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706093}

net/url_request/url_request.cc

@@ -432,6 +432,10 @@ void URLRequest::SetLoadFlags(int flags) {
     SetPriority(MAXIMUM_PRIORITY);
 }
 
+void URLRequest::SetDisableSecureDns(bool disable_secure_dns) {
+  disable_secure_dns_ = disable_secure_dns;
+}
+
 // static
 void URLRequest::SetDefaultCookiePolicyToBlock() {
   CHECK(!g_url_requests_started);
@@ -566,6 +570,7 @@ URLRequest::URLRequest(const GURL& url,
       first_party_url_policy_(NEVER_CHANGE_FIRST_PARTY_URL),
       load_flags_(LOAD_NORMAL),
       privacy_mode_(PRIVACY_MODE_ENABLED),
+      disable_secure_dns_(false),
 #if BUILDFLAG(ENABLE_REPORTING)
       reporting_upload_depth_(0),
 #endif

net/url_request/url_request.h

@@ -547,6 +547,9 @@ class NET_EXPORT URLRequest : public base::SupportsUserData {
   // the request is redirected.
   PrivacyMode privacy_mode() { return privacy_mode_; }
 
+  // Returns whether secure DNS should be disabled for the request.
+  bool disable_secure_dns() { return disable_secure_dns_; }
+
   void set_maybe_sent_cookies(CookieStatusList cookies);
   void set_maybe_stored_cookies(CookieAndLineStatusList cookies);
 
@@ -574,6 +577,9 @@ class NET_EXPORT URLRequest : public base::SupportsUserData {
   // the priority of this request must already be MAXIMUM_PRIORITY.
   void SetLoadFlags(int flags);
 
+  // Sets whether secure DNS should be disabled for the request.
+  void SetDisableSecureDns(bool disable_secure_dns);
+
   // Returns true if the request is "pending" (i.e., if Start() has been called,
   // and the response has not yet been called).
   bool is_pending() const { return is_pending_; }
@@ -859,6 +865,7 @@ class NET_EXPORT URLRequest : public base::SupportsUserData {
   int load_flags_;  // Flags indicating the request type for the load;
                     // expected values are LOAD_* enums above.
   PrivacyMode privacy_mode_;
+  bool disable_secure_dns_;
 
   CookieStatusList maybe_sent_cookies_;
   CookieAndLineStatusList maybe_stored_cookies_;

net/url_request/url_request_http_job.cc

@@ -337,6 +337,7 @@ void URLRequestHttpJob::Start() {
 
   request_info_.network_isolation_key = request_->network_isolation_key();
   request_info_.load_flags = request_->load_flags();
+  request_info_.disable_secure_dns = request_->disable_secure_dns();
   request_info_.traffic_annotation =
       net::MutableNetworkTrafficAnnotationTag(request_->traffic_annotation());
   request_info_.socket_tag = request_->socket_tag();

net/url_request/url_request_unittest.cc

@@ -1227,6 +1227,44 @@ TEST_F(URLRequestTest, NetworkDelegateProxyError) {
   EXPECT_EQ(1, network_delegate.completed_requests());
 }
 
+TEST_F(URLRequestTest, SkipSecureDnsDisabledByDefault) {
+  MockHostResolver host_resolver;
+  TestNetworkDelegate network_delegate;  // Must outlive URLRequest.
+  TestURLRequestContext context(true);
+  context.set_network_delegate(&network_delegate);
+  context.set_host_resolver(&host_resolver);
+  context.Init();
+
+  TestDelegate d;
+  std::unique_ptr<URLRequest> req(
+      context.CreateRequest(GURL("http://example.com"), DEFAULT_PRIORITY, &d,
+                            TRAFFIC_ANNOTATION_FOR_TESTS));
+  req->Start();
+  d.RunUntilComplete();
+
+  EXPECT_FALSE(host_resolver.last_secure_dns_mode_override().has_value());
+}
+
+TEST_F(URLRequestTest, SkipSecureDnsEnabled) {
+  MockHostResolver host_resolver;
+  TestNetworkDelegate network_delegate;  // Must outlive URLRequest.
+  TestURLRequestContext context(true);
+  context.set_network_delegate(&network_delegate);
+  context.set_host_resolver(&host_resolver);
+  context.Init();
+
+  TestDelegate d;
+  std::unique_ptr<URLRequest> req(
+      context.CreateRequest(GURL("http://example.com"), DEFAULT_PRIORITY, &d,
+                            TRAFFIC_ANNOTATION_FOR_TESTS));
+  req->SetDisableSecureDns(true);
+  req->Start();
+  d.RunUntilComplete();
+
+  EXPECT_EQ(net::DnsConfig::SecureDnsMode::OFF,
+            host_resolver.last_secure_dns_mode_override().value());
+}
+
 // Make sure that NetworkDelegate::NotifyCompleted is called if
 // content is empty.
 TEST_F(URLRequestTest, RequestCompletionForEmptyResponse) {