Add a new set_quic_flags QUIC cronet option which allows QUIC flags to be set.

Bug: 984738
Change-Id: Iff1257a3cb730fad8215b2bb9a755c7dcd67aed5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1821859Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699953}

components/cronet/url_request_context_config.cc

@@ -90,6 +90,7 @@ const char kQuicHostWhitelist[] = "host_whitelist";
 const char kQuicEnableSocketRecvOptimization[] =
     "enable_socket_recv_optimization";
 const char kQuicVersion[] = "quic_version";
+const char kQuicFlags[] = "set_quic_flags";
 
 // AsyncDNS experiment dictionary name.
 const char kAsyncDnsFieldTrialName[] = "AsyncDNS";
@@ -551,6 +552,19 @@ void URLRequestContextConfig::ParseAndSetExperimentalOptions(
         }
       }
 
+      std::string quic_flags;
+      if (quic_args->GetString(kQuicFlags, &quic_flags)) {
+        for (const auto& flag :
+             base::SplitString(quic_flags, ",", base::TRIM_WHITESPACE,
+                               base::SPLIT_WANT_ALL)) {
+          std::vector<std::string> tokens = base::SplitString(
+              flag, "=", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+          if (tokens.size() != 2)
+            continue;
+          SetQuicFlagByName(tokens[0], tokens[1]);
+        }
+      }
+
     } else if (it.key() == kAsyncDnsFieldTrialName) {
       const base::DictionaryValue* async_dns_args = nullptr;
       if (!it.value().GetAsDictionary(&async_dns_args)) {

components/cronet/url_request_context_config_unittest.cc

@@ -70,6 +70,10 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   options.SetPath({"QUIC", "close_sessions_on_ip_change"}, base::Value(true));
   options.SetPath({"QUIC", "race_cert_verification"}, base::Value(true));
   options.SetPath({"QUIC", "connection_options"}, base::Value("TIME,TBBR,REJ"));
+  options.SetPath(
+      {"QUIC", "set_quic_flags"},
+      base::Value("FLAGS_quic_reloadable_flag_quic_supports_tls_handshake=true,"
+                  "FLAGS_quic_reloadable_flag_quic_enable_version_99=true"));
   options.SetPath({"AsyncDNS", "enable"}, base::Value(true));
   options.SetPath({"NetworkErrorLogging", "enable"}, base::Value(true));
   options.SetPath({"NetworkErrorLogging", "preloaded_report_to_headers"},
@@ -140,6 +144,10 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   std::string options_json;
   EXPECT_TRUE(base::JSONWriter::Write(options, &options_json));
 
+  // Initialize QUIC flags set by the config.
+  FLAGS_quic_reloadable_flag_quic_supports_tls_handshake = false;
+  FLAGS_quic_reloadable_flag_quic_enable_version_99 = false;
+
   URLRequestContextConfig config(
       // Enable QUIC.
       true,
@@ -191,6 +199,9 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   quic_connection_options.push_back(quic::kREJ);
   EXPECT_EQ(quic_connection_options, params->quic_params.connection_options);
 
+  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_supports_tls_handshake);
+  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_enable_version_99);
+
   // Check Custom QUIC User Agent Id.
   EXPECT_EQ("Custom QUIC UAID", params->quic_params.user_agent_id);